JP2004298244A - Hood for endoscope - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hood for endoscopes which can keep itself in contact with the entire inner wall of the lumen accurately within a narrow lumen tube while making almost uniform pressing forces workable thereon. <P>SOLUTION: The hood 40 mounted on the hard distal part 2c of an insertion tube part 2 comprises a fit fixing part 41 and a hood body part 42 protruding by a specified length from the tip face of the hard distal part 2c. The hood body part 42 presents an askew cut cylindrical part in shape and the length of the protrusion is the shortest at the upper position thereof, the longest on the lower part side therefrom and varies successively therebetween. The thickness of the tip part of the hood body part 42 is the largest on the upper part side thereof, the least on the lower part side thereof and varies successively in the portion therebetween. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a hood attached to a distal end of an insertion portion of an endoscope, and is particularly preferably used for an endoscope that enables an inner wall of a body cavity to be magnified from a close position in a narrow body cavity tube or the like. It relates to a mirror hood.
[0002]
[Prior art]
The endoscope is provided with an illumination unit and an observation unit at the distal end of the insertion unit, and performs diagnosis such as observing an inner wall of a body cavity and finding a lesion under illumination from the illumination unit. If necessary, a treatment tool is inserted to perform treatment such as removal of an affected part, hemostasis, etc., and sampling of cells. In order to accurately observe the inside of a body cavity with an endoscope, the observation section provided on the distal end surface of the insertion section must be at a certain interval with respect to the inner wall of the body cavity, and this interval does not change during observation. Must be maintained.
[0003]
In particular, in recent years, a so-called magnifying endoscope, in which the distal end portion of the insertion portion is arranged at a position very close to the inner wall of the body cavity and an image is taken while enlarging the inner wall of the body cavity, has been put to practical use. In an endoscope, the observation depth is extremely short. Therefore, when inspecting and diagnosing the inner wall of the body cavity with the magnifying endoscope, if the distance between the observation section and the inner wall of the body cavity changes even a little, the focus is greatly shifted, and a clear image cannot be obtained. For this reason, by attaching a hood to the tip of the insertion portion and observing the inner wall of the body cavity, the tip of the hood is brought into contact with the inner wall of the body cavity so that the distance between the tip of the insertion portion and the inner wall of the body cavity can be kept constant. An apparatus configured to perform an inspection or diagnosis while holding the information is conventionally known (for example, see Patent Document 1).
[0004]
[Patent Document 1]
JP-A-2002-51970 (page 2-3, FIG. 2-3)
[0005]
[Problems to be solved by the invention]
The configuration of the hood for an endoscope according to the above-described conventional technique includes a portion fitted to the distal end hard portion of the insertion portion, and a portion projecting from the distal end hard portion. , Its thickness dimension and protrusion length are constant. Therefore, when the inner wall of the body cavity is at an extension of the insertion direction of the insertion section, when performing the inspection, the entire front end of the hood can be pressed against the inner wall of the body cavity. The distance between the part and the inner wall of the body cavity can be kept constant. However, there are narrow places such as thin body cavities as inspection and diagnosis places by an endoscope.
[0006]
As described above, when inspecting the inner wall of the body cavity in a narrow place, the angle portion in the insertion section must be curved, and the observation section of the hard distal end portion must be directed toward the inner wall of the body cavity. In this case, it is sufficient that the angle part can be bent by approximately 90 °, but in a narrow body cavity tube, the angle part cannot be bent at this angle, or even if the angle part can be bent, the angle part presses the inner wall of the body cavity. However, there is a problem that the subject is forced to suffer. When the angle portion is bent at a shallow angle, the entire distal end of the hood cannot be pressed against the inner wall of the body cavity, and the distal end portion of the insertion portion becomes unstable.
[0007]
The present invention has been made in view of the above points, and it is an object of the present invention to securely contact the entire inner wall of a body cavity in a narrow body cavity tube and apply a substantially uniform pressing force. It is an object of the present invention to provide an endoscope hood capable of performing the above.
[0008]
[Means for Solving the Problems]
In order to achieve the above-mentioned object, the present invention relates to a hood to be attached to an endoscope having an insertion portion provided by connecting a hard end portion provided with a lighting portion and an observation portion on a front end surface to an angle portion. And a hood main body projecting forward of the rigid distal end portion from the coupling portion, the hood main body portion having a maximum bending angle by the angle portion. The side has the shortest protruding length from the distal end hard portion and the distal end portion is the thickest, and a position at an angle of 180 ° from this position has the longest protruding length from the distal end hard portion, and It is characterized in that the portion is the thinnest, and the length and thickness of the protrusion are configured to change continuously between the portions.
[0009]
The angle portion is configured to be capable of being bent by remote control from a main body operation portion to which the base end portion of the insertion portion is connected so as to direct the distal end hard portion in a desired direction. The bending direction of the angle portion is generally configured to be able to bend in four directions, for example, up and down and left and right. However, the angles that can be bent in the above-described directions are not the same, and the upward bending angle is usually the largest. Therefore, the hood is attached to the hard distal end portion based on this direction. In other words, the position at the maximum bending angle, specifically, the position on the innermost side when bent upward, is the thickest, and the length of projection from the hard distal end is also minimized. Further, a position 180 ° in the circumferential direction from this position, that is, a position on the opposite side in the circumferential direction is the thinnest, and the protruding length is the longest. In the meantime, the protruding length and the wall thickness are continuously changed.
[0010]
As described above, when the hood is mounted on the distal end hard portion of the insertion portion, the position in the rotation direction must be stable. For this purpose, a configuration is provided in which anti-rotation means is provided between the distal end hard portion and the fitting connection portion of the hood. As the rotation preventing means, for example, it is possible to adopt a configuration in which a flat portion is formed in the hard tip portion, and a flat surface corresponding to the flat surface of the hard tip portion is provided in the fitting connection portion of the hood. it can. By setting the outer surface of the hood main body to have a cylindrical shape and the inner surface side to be continuously reduced in thickness toward the distal end side, the visual field range can be widened as much as possible.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the drawings. First, FIG. 1 shows a schematic configuration of an endoscope. In the drawing, 1 is a main body operation unit, 2 is an insertion unit, and 3 is a universal cord. The insertion portion 2 includes a flexible portion 2a, an angle portion 2b, and a hard distal end portion 2c in this order from the side connected to the main body operation portion 1. The angle portion 2b is operated by an angle operation means 4 provided in the main body operation portion 1. It can be bent vertically and horizontally. This operation is for orienting the distal end hard portion 2c in an arbitrary direction. The distal end surface of the distal end hard portion 2c includes an illumination unit 5, an observation unit 6, a treatment instrument outlet 7, and an observation unit cleaning nozzle 8. (See FIG. 5).
[0012]
Here, the angle portion 2b is normally bendable up and down and left and right, and in these bending directions, the upper part, that is, the direction shown by the phantom line in FIG. Specifically, the upward bending angle is 200 ° or more, and the other directions, that is, the downward and leftward and rightward directions are about 90 ° to 100 °. As described above, the upward bending angle is set to be the largest because the operation in this direction is frequently performed. When changing the observation visual field in the body cavity, the upward bending angle is most often used.
[0013]
FIG. 2 shows a cross section of the distal end hard portion 2c of the insertion portion 2. In the sectional position in this figure, the observation means 10 attached to the observation section 6 and the treatment tool insertion channel 11 connected to the treatment tool outlet 7 are located. In the figure, reference numeral 20 denotes a distal end main body constituting the distal end hard portion 2c, and reference numeral 21 denotes a distal end cap. The observation unit 10 has an objective optical system 12 and an imaging unit 13, and the imaging unit 13 faces an imaging surface in a direction parallel to the optical axis of the objective optical system 12. Therefore, the imaging means 13 protrudes above the objective optical system 12 in the distal end body 20. On the other hand, the treatment instrument insertion channel 11 has a pipe 14 inserted into a passage formed in the distal end main body 20, and a tube 15 is fitted to the base end of the pipe 14. It extends from the angle part 2b to the main body operation part 1 via the flexible part 2a. Therefore, the treatment instrument insertion channel 11 has substantially the same diameter in the distal end body 20.
[0014]
The angle portion 2b connected to the distal end hard portion 2c is formed by pivotally mounting a predetermined number of angle rings, and the foremost ring 30 is fitted to the distal end body 20 of the distal end rigid portion 2c by a predetermined length. The angle ring including the leading-edge ring 30 is covered with a metal net 31 and further covered with a coating layer 32. Then, the distal end of the coating layer 32 is fitted into the step 22 formed on the outer peripheral surface on the distal end side of the distal end main body 20, and the fixing portion 33 formed by thread winding and bonding is formed. The distal end cap 21 is attached to the distal end portion of the distal end body 20, and the fixing portion 33 extends to the end position of the distal end cap 21. Thus, even if the distal end body 20 is formed of metal from the viewpoint of strength, workability, and the like, the entire outer surface of the insertion section 2 is maintained in an electrically insulated state.
[0015]
In the endoscope configured as described above, the hood 40 shown in FIGS. 3 and 4 is detachably attached to the distal end hard portion 2c. The hood 40 is made of, for example, transparent silicon rubber or the like, and has a fitting fixed portion 41 fitted so as to cover almost the entire outer surface of the distal end hard portion 2c, and a predetermined length from the distal end surface of the distal end hard portion 2c. And a hood main body 42 protruding only therefrom.
[0016]
The fitting / fixing portion 41 includes a tip cap accommodation portion 43 in which the tip cap 21 is accommodated, and a coating layer accommodation portion 44 in which the coating layer 32 is accommodated. The tip cap accommodation portion 43 has a smaller diameter than the coating layer accommodation portion 44. It has become. In addition, as described above, the imaging unit 13 is disposed above the distal end main body 20, and the objective optical system 12 is disposed at the position of the step 22 of the distal end main body 20. The upper part at the disposition position is scraped off to form a substantially flat part. Then, as shown in FIG. 5, a depression 23 (or a flat surface) is formed at an upper position on the outer peripheral surface of the tip cap 21. A substantially flat positioning portion 43a is formed in the tip cap housing portion 43 of the fitting / fixing portion 41 of the hood 40 at a position corresponding to the depression 23 of the tip cap 21. Therefore, when the hood 40 is mounted on the distal end hard portion 2c, the hood 40 and the distal end hard portion 2c are mounted by mounting the hood 40 at a position where the positioning portion 43a of the distal end cap housing portion 43 and the recess 23 of the distal end cap 21 coincide with each other. And the hood 40 is held so that the hood 40 is not displaced in the rotational direction.
[0017]
The hood main body portion 42 is formed in an annular shape, and when the hood 40 is mounted on the distal end hard portion 2c, it projects from the end surface of the distal end cap 21 by a predetermined length. The hood main body 42 has a shape in which a cylindrical portion is cut obliquely, and when the upper position, that is, when the angle portion 2b is curved, the inwardly curved side has the shortest protruding length, Then, the position at 180 °, that is, the lower position side, is the longest, during which the protruding length changes continuously. Therefore, the thickness of the tip portion of the hood main body 42 is the thickest on the upper side and the thinnest on the lower side, and the thickness between the portions between them is continuously changing.
[0018]
The hood body 42 has a cylindrical outer peripheral surface and a tapered portion 42a whose inner peripheral surface increases in diameter as it goes toward the distal end. Moreover, the taper angle is the largest on the upper side and the smallest on the lower side, and the angle changes continuously during that time. This is because, as shown in FIG. 5, the observation means 10 is provided at a position displaced upward from the center position of the distal end surface of the distal end hard portion 2c, so that the upper side has a larger taper angle than the lower side. The reason for this is to increase the viewing angle as much as possible by increasing the size.
[0019]
The present embodiment is configured as described above, and a method of inspecting and diagnosing a body cavity with the hood 40 attached to the insertion section 2 of the endoscope will be described. Here, this endoscope is suitable for examining the state of the mucous membrane of the cavity wall in a thin body cavity such as the esophagus or the duodenum. That is, as shown in FIG. 6, the insertion section 2 is inserted into a thin body cavity, and is used to closely examine the state of the mucous membrane of the cavity wall at a close position.
[0020]
Since the insertion direction of the insertion section 2 is in front of the body cavity tube, in order to inspect the cavity wall, the angle section 2b must be curved so that the visual field of the observation section 5 is turned so as to face the cavity wall. Must. Moreover, it is necessary to provide an interval between the distal end surface of the distal end hard portion 2c and the interval between the observation unit 5 and the cavity wall so as not to change during the examination so that the distal end surface does not adhere to the cavity wall. The hood 40 is attached to the rigid distal end portion 2c because the distal end surface of the hood main body portion 42 of the hood 40 is brought into contact with the cavity wall so that a predetermined distance is provided between the observation unit 5 and the cavity wall. This is to separate them. In addition, the tip of the hood body 42 is slanted for this reason. Accordingly, the angle operation can be easily performed in a narrow place, the pressing force on the cavity wall is suppressed to a minimum, and the pain on the subject can be reduced.
[0021]
The protruding length of the distal end hard portion 2c of the hood main body portion 42 of the hood 40 from the distal end surface is adjusted so that the objective optical system 12 of the observation means 10 is accurately focused at this distance. Here, the objective optical system 12 having a magnification changing mechanism is used, and when inspecting the cavity wall, magnified observation by magnification change is performed. As described above, when the magnification observation is performed, if the depth of focus becomes shallow and the distance between the observation unit 5 and the cavity wall changes even slightly, the image is out of focus and a clear image cannot be obtained. Factors that change the distance between the observation unit 5 and the cavity wall include movement of the observation unit 5 and pulsation in the body cavity.
[0022]
The top end of the hood body 42 of the hood 40 has the shortest projection length at the upper side in the bending direction of the angle portion 2b, and has the largest wall thickness, and the lower side opposite to the projection length has the same length. Is the longest and the thinnest. That is, when the angle portion 2b is curved upward as shown by the arrow in FIG. 6, the distal end surface of the distal end hard portion 2c abuts at a position where the upper side in this bending direction is closest to the cavity wall. And the opposite side abuts at the position furthest away from the cavity wall. Moreover, the upper side of the hood main body 42 has the highest rigidity, and the lower side has the highest flexibility.
[0023]
By bending the angle portion 2b, the tip of the hood main body 42 comes into contact with the cavity wall, so that the hood main body 42 comes into contact with the cavity wall by an arc-shaped operation. Then, due to this arc movement, the radius of curvature at the time of bending differs between upper and lower portions of the hood main body 42. That is, the radius of curvature on the upper side is small, and the radius of curvature on the lower side is large. When the radius of curvature during bending is small, the component force in the direction of pressing against the cavity wall is small, and when the radius of curvature is large, the component force in the direction of pressing against the cavity wall is large. When the angle portion 2b of the hood body portion 42 is curved, the upper portion having a smaller radius of curvature is thicker and the lower portion having a larger radius of curvature is thinner. It can be received more effectively, and the lower side is elastically deformed by the pressing force against the cavity wall.
[0024]
As a result, a substantially uniform pressing force acts on the cavity wall over the entire circumference of the hood main body 42. This stabilizes the state in which the distance between the observation section 5 disposed on the distal end surface of the distal end hard section 2c of the insertion section 2 and the cavity wall is kept substantially constant. In addition, the movement of the cavity wall caused by the pulsation in the body cavity or the like is restricted by the pressing force of the hood main body portion 42 against the cavity wall. As a result, a clear image can be obtained even during magnification observation (for example, about 100 times).
[0025]
The hood 40 attached to the distal end hard portion 2c has directionality as described above, but between the positioning portion 43a of the distal end cap housing portion 43 in the fitting and fixing portion 41 and the recess 23 of the distal end cap 21. , The displacement in the rotation direction when the hood 40 is attached is reliably prevented, and the displacement in the rotation direction does not occur during use. In addition, when the inner diameter of the fitting / fixing portion 41 of the hood 40 is reduced, and the hood 40 is fitted to the distal end hard portion 2c, the hood 40 is attached so as to press against the portion having the largest diameter, that is, the fixing portion 33. Thereby, the mounting position of the hood 40 can be adjusted to some extent. For this reason, the distance between the observation unit 5 and the cavity wall of the objective optical system 12, particularly at the maximum magnification, can be adjusted so that the hood 40 is located at a position where accurate focusing can be achieved.
[0026]
【The invention's effect】
Since the present invention is configured as described above, the tip of the hood can reliably contact the entire inner wall of the body cavity in a narrow body cavity tube, and a substantially uniform pressing force can be applied. There are effects such as the observation function at the time of magnifying observation to be shallow can be remarkably improved.
[Brief description of the drawings]
FIG. 1 is an overall configuration diagram showing a general endoscope.
FIG. 2 is a sectional view of a distal end portion of an insertion section.
FIG. 3 is a cross-sectional view of a hood mounted on an insertion portion in the embodiment of the present invention.
FIG. 4 is a left side view of FIG. 3;
FIG. 5 is a front view of a distal end hard portion in the insertion portion.
FIG. 6 is an operation explanatory view showing a state in which an inspection with an endoscope is performed.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Main body operation part 2 Insertion part 2a Flexible part 2b Angle part 2c Tip hard part 6 Observation part 10 Observation means 12 Objective optical system 20 Tip part main body 21 Tip cap 22 Step part 23 Depression 40 Food 41 Fitting fixing part 42 Food main part 42a Tapered section 43 Tip cap storage section 43a Positioning section 44 Coating layer storage section

Claims (3)

A hood attached to an endoscope having an insertion portion provided by connecting a distal end hard portion provided with a lighting portion and an observation portion on a distal end surface to an angle portion,
A fitting connecting portion fitted to the distal end hard portion, and a hood main body portion extending from the connecting portion to the front of the distal end hard portion,
The hood main body portion has a shortest protruding length from the hard distal end portion on the side of the maximum bending angle due to the angle portion and the thickest end portion, and a position at an angle of approximately 180 ° from this position is the tip end. The endoscope is characterized in that the projection length from the hard portion is the longest and the tip portion is the thinnest, and the projection length and the wall thickness are changed continuously between them. hood. The hood for an endoscope according to claim 1, wherein rotation preventing means is provided between the distal end hard portion and the fitting connection portion. 2. The hood for an endoscope according to claim 1, wherein the hood main body is formed such that an outer surface thereof has a cylindrical shape and an inner surface side thereof has a continuously decreasing thickness toward a distal end side.

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