JP3273079B2 - Bending part structure of endoscope - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bending portion structure for bending an insertion portion of an endoscope.

[0002]

2. Description of the Related Art A bending portion in an insertion portion of a general endoscope uses a plurality of bending pieces for a bending core material. That is, the curved core material is obtained by arranging a plurality of curved pieces in series along the longitudinal axis direction of the insertion portion, and rotatably connecting adjacent curved pieces.

[0003] In particular, in the structure disclosed in Japanese Patent Application Laid-Open No. 59-11827, a so-called helical tube in which projections are provided on a helical member at a specific period, is formed as a curved core material.

[0004]

In the conventional bending portion structure having a bending piece, the shape of each component is complicated, the number of components is large, and the labor for assembling them is enormous. There was a problem that there was a problem.

On the other hand, JP-A-59-11827 discloses
In a curved portion structure composed of a spiral tube provided with a projection at a specific period, the projection serves as a fulcrum when the abutting portion between the helical member and the helical member is curved. Therefore, when it performs the bending operation, it does not determine the rotation center axis of the bending portion in a state of always intersecting at right angles to the longitudinal direction of the bending portion. For this reason, when a traction force acts on the spiral tube during the bending operation, there is a problem that the bent portion is twisted around its longitudinal axis.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and has as its object the purpose of the present invention is to provide a simple and small number of parts, which can be easily assembled, and which can be reliably bent only in a desired direction. An object of the present invention is to provide a bending structure of an endoscope which does not cause torsion.

[0007]

SUMMARY OF THE INVENTION The present invention relates to a bending portion structure of an endoscope in which a bending structure is formed by forming an elastic strip in a spiral shape. Providing a convex portion for locally contacting the body part, the point of contact is a center of rotation when performing a bending operation,
The rotation center line connecting them is set so as to intersect substantially perpendicularly to the direction of the central axis of the curved structure. It bends only in a desired direction, and in particular, the bent portion is not twisted.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described with reference to FIGS. FIG. 2 shows an endoscope 1 and a peripheral system according to this embodiment. The endoscope 1 has an insertion section 2 and an operation section 3, and the insertion section 2 is configured by sequentially connecting a flexible tube 5, a bending section 6, and a distal end section 7 from the hand side. The bending section 6 is bent via an operation wire 17 to be described later by rotating a rotation knob 9 provided in the operation section 3.

A cable 11 extends from the operation unit 3, and a connector 13 for connecting to a video control unit 12, which also serves as a light source for illumination, is provided at the extension end of the cable 11. In FIG. 2, reference numeral 14 denotes a TV monitor. The operation unit 3 is provided with a plurality of operation switches 10.

FIG. 3 shows the structure of the insertion section 2. Inside the insertion portion 2, a light guide fiber 15, a channel tube 16 for inserting forceps, an operation wire 17, and the like are inserted and arranged. The light guide fiber 15 is connected to an illumination light source in the control unit 12 through the cable 11.

A CCD (not shown) is provided at the tip 7 of the insertion section 2.
An image sensor is provided, and an image signal detected by the image sensor is transmitted to the control unit 12 through a signal line (not shown). The TV monitor 14 displays the captured image.

There are two operation wires 17 inserted into the inside of the insertion portion 2, and these are separately biased vertically above and below, respectively. The distal ends of these operation wires 17 are connected to the distal end portion 7. The operation wire 17 in the flexible tube 5 is guided through a wire guide 18. The proximal end of the operation wire 17 is connected to a traction mechanism (not shown) for bending operation of the operation unit 3. Then, by selectively rotating the rotation knob 9 in one direction, the one operation wire 17 is pulled, and the bending portion 6 is bent in the pulling direction. FIG. 3A shows a state of the bending portion 6 in a neutral state, and FIG. 3B shows a bending state of the bending portion 6 bent downward due to pulling of the lower operation wire 17.

On the other hand, the bending portion 6 of the insertion portion 2 is formed in a tubular shape as shown in FIG. 3, and the bending structure 21 is formed as follows. In addition, the outer periphery of the curved structure 21 is covered with an outer skin 22.

That is, as shown in FIG. 1, the curved structure 21 is formed by forming a strip-shaped elastic strip 23 into a single-turn coil shape. FIG. 1A is a front view, FIG. 1B is a side view, and FIG. 1C is a developed view.

As shown in FIG. 1C, a strip-shaped elastic strip 2
The width of 3 is constant, and convex portions 24 are provided on both sides thereof alternately at right and left at equal intervals. When the coil diameter of the curved structure 21 is d, the interval between the projections 24 is
It is set to be “(π / 2) d”. Also, the width of the elastic strip 23 and the height of the projection 24 are all equal,
"H".

Therefore, by forming the band-shaped elastic strip 23 into a helical shape with the same diameter, the left and right convex portions 24 close to phosphorus are formed.
Whereas its central axis L _1, it is disposed at a position of point symmetry.
At this time, since the height of the left and right convex portions 24 and the width of the elastic strip 23 all match, as shown in FIG. 1A, the tip of the convex section 24 that abuts against the side end face of the elastic strip 23 is removed. Although the rotation center line L ₂ of the curved portion 6 when the connecting line is curved, this rotation center line L _2, the center axis L ₁ of the curved structure 21
Intersect at right angles to

From this, when bending, the rotation center line L of the bending portion 6
Numeral ₂ is orthogonal to the central axis L ₁ of the curved structure 21 and curves in a plane including the central axis L ₁ . Therefore, by pulling the operation wire 17, the bending structure 21, that is, the bending portion 6
Does not exert a torsional force on the bending portion 6.

Further, when the operation wire 17 is pulled to bend the bending portion 6, the bending structure 21 is pulled, and is particularly strongly compressed on one side. However, the left and right convex parts 2 approaching phosphorus
4 are arranged at point-symmetric positions with respect to the center axis L ₁ of the curved structure 21, and each abuts against the side end surface of the elastic strip 23, so that the curved structure 21 is not crushed. When the bending portion 6 is bent, the bending portion 6, that is, the bending structure 21 does not shrink as shown in FIG.

FIG. 4 shows an example of a curved structure 21 according to a second embodiment of the present invention. 4 (a) is a front view, FIG. 4 (b) is a side view, and FIG. 4 (c) is a developed view.

As shown in FIG. 4C, the belt-shaped elastic strip 2
The width of 3 is constant, and convex portions 24 are integrally provided on both sides thereof. The interval between the convex portions 24 is the same as that of the curved structure 21.
When the coil diameter is d, it is set under the condition of the equation shown in FIG. That is, a point, b point, c point, d point,
.. are disposed at points a, b,. Points a and d are arranged on one side, and points b and c are arranged on the other side.

The distance between the point a and the point b is "(π / 4)
d ”. The distance between the point b and the point c is set to be “(5/4) πd”. Also, c
The distance between the point and the point d and the distance between the point d and the point a are “(π / 4)
d ”. Therefore, point a, b
Are periodically arranged as points, c, d, a, b,. In addition, the width of the elastic strip 23 and the height of the projection 24 are all equal, and are “h”.

Therefore, by forming the strip-shaped elastic strip 23 into a spiral with the same diameter, the left and right projections 24 close to phosphorus are formed.
Whereas its central axis L _1, it is disposed at a position of point symmetry.
At this time, since the height of the left and right protrusions 24 and the width of the elastic strip 23 are all the same, the tip of the protrusion 24 that abuts against the side end face of the elastic strip 23 as shown in FIG. connecting line, as a rotation center line L ₂ of the curved portion 6 at the time of bending. That is, as in the case of the first embodiment described above, intersecting at right angles the central axis of the bending structure 21 L ₁ and the rotation center line L _2.

However, since the rotation center line L ₂ is of two types, the phases of which are shifted by “π / 2” around the center axis L ₁ , the points of contact by the projections 24 are arranged alternately up, down, left and right. It becomes the rotation center of the bending operation in the direction. Therefore, when using the curved structure 21, the curved portion 6 of the insertion portion 2 can be curved without twisting in four directions by using the operation wire 17 in the same manner as described above.

FIG. 5 shows an example of a curved structure 21 according to a third embodiment of the present invention. FIG. 5A is a front view, and FIG. 5B is a developed view. As shown in FIG. 5 (b), four consecutive convex portions 24, two on each side, are provided as a set, and the convex portions 24 at points a and d are provided on one of the same side edges,
Protrusions 24 at points b and c are provided on the other edge, and these four are made into one set. Then, a plurality of such sets are provided. In addition, the interval between the adjacent points of each set is set to be “(π / 4) d” when the coil diameter of the curved structure 21 is d.

The distance between a point d in a certain set and a point a in the next set is "(5/4) πd". Convex part 24 in each set
And height, change the width of the portion of the flexible ribs 23 providing these together, one to match the same "h", "h _1" and the value for each set, sequentially and "h _2" larger or smaller I do.

Therefore, by forming the belt-shaped elastic strip 23 into a spiral with the same diameter, the interval between the rotation centers when the bending structure 21 is bent can be changed. For example, toward the distal end from the proximal side, in order to increase the angle of rotation by narrowing the interval between the rotational center line L ₂ is,
The height of the convex portion 24 and the width “h” of the elastic strip 23 may be reduced toward the distal end. This leads to a sharper bending operation, which is preferable when the lumen into which the insertion section 2 of the endoscope 1 is inserted is narrow.

FIG. 6 shows an example of a curved structure 21 according to a fourth embodiment of the present invention. FIG. 6A is a front view, FIG. 6B is a side view, and FIG. 6C is a developed view.

In the fourth embodiment, two elastic strips 23 are used.
This is an example of forming a two-turn winding structure 21 composed of a and 23b. The relationship between the intervals of each convex portion 24 is as follows.
As shown in FIG. 6C, when the coil diameter is d. That is, the interval between the adjacent convex portions 24 is alternately set to “(π
/ 4) d "and" (π / 2) d ". According to this relationship, as in the above-described second embodiment, the curved structure 21 is
Two rotation center line L ₂ suitable to rotate in the direction can be obtained.

FIG. 7 shows an example of a curved structure 21 according to a fifth embodiment of the present invention. FIG. 7A is a front view, and FIG. 7B is a developed view. The curved structure 21 shown in the fifth embodiment is formed from two wires 23 into two turns. That is, as shown in FIG.
4 is obtained by bending the wire. In addition, each protrusion 2
As in the fourth embodiment shown in FIG. 6B, when the coil diameter of the curved structure 21 is d, as shown in FIG.
As shown in (b), the interval between the adjacent convex portions 24 is alternately set to “(π / 4) d” and “(π / 2) d”.

According to this, two kinds of rotation center lines L ₂ suitable for rotating in four directions are obtained, as in the above-described second embodiment, in which the bending structure 21 is easily manufactured.
Suitable for bending in four directions.

FIGS. 8 and 9 show a treatment tool 30 which is inserted into a body cavity through the channel tube 16 of the endoscope 1 to capture gall bladder stones. This treatment tool 30 is provided with an operation section 32 at the base end of a sheath 31 and a sheath 3
As shown in FIG. 8 (b), a grip portion 34 made of a pipe 33 made of a shape memory alloy is provided at the distal end portion 1.

This gripping part 34 has a pipe 33 of "U"
, And the middle part is the tip. Both ends of the pipe 33 are guided to the operation unit 32 through the inside of the sheath 31. Further, both ends of the pipe 33 are connected to a hot water pump 36 via a connecting tube 35. By operating the hot water pump 36, hot water can be circulated in the pipe 33.

Next, the function of the treatment tool 30 will be described.
A grip part 34 made of a pipe 33 made of a shape memory alloy
9A is in the straightened state shown in FIG. 9A near the body temperature, keeps the shape protruding from the distal end of the sheath 31, and circulates water around 42 ° C. exceeding the body temperature in the pipe 33, thereby obtaining FIG. The curled shape shown in b) is obtained.

Therefore, the sheath 31 of the treatment instrument 30 is inserted into the bile duct or the like through the channel tube 16 of the endoscope 1, and when the distal end of the grip portion 34 is inserted to the side of the calculus 37, the sheath 31 is inserted into the pipe 33. By circulating hot water,
The calculus 37 is captured by curling to the state shown in FIG.

FIG. 10 shows a biopsy forceps 4 which is inserted into a body cavity through the channel tube 16 of the endoscope 1 to perform a biopsy.
It is an example of 0. The tip cup 41 of the biopsy forceps 40 is opened and closed by circulating water through a pair of pipes 42 and 43 made of a shape memory alloy as in the above-described embodiment. FIG. The tip cup 41 is closed by circulating water at about the body temperature in the pipes 42 and 43, and FIG.
1 shows the opened state.

FIG. 11 shows an example of a basket forceps 50 which is inserted into a body cavity through the channel tube 16 of the endoscope 1 to capture gall bladder stones. It has a basket portion 54 having a structure in which the tip portions 53 of a pair of pipes 51 and 52 made of a shape memory alloy are joined by bending and joining the bent tips. When the warm water of the body temperature is circulated in the pipes 51 and 52, the basket portion 54 becomes the one shown in FIG.
It is in a closed state as shown by. In this state, the stone 55
When hot water higher than the body temperature is circulated in the pipes 51 and 52 at the time of insertion to the side portion of FIG.
Open as shown in (b) and catch the calculus 55. Further, by circulating the water lowered to the body temperature in the pipes 51 and 52, the basket portion 54 is closed and the calculus 55 is held.

[0037]

As described above, according to the present invention, it is possible to easily assemble a simple and small number of parts, to be surely bent only in a desired direction, and to prevent twisting when bending. An endoscope bending structure can be provided.

[Brief description of the drawings]

FIG. 1 shows a curved structure according to a first embodiment of the present invention;
(A) is its front view, (b) is its side view, (c) is its development view.

FIG. 2 is an external view of the endoscope and its peripheral system according to the first embodiment of the present invention.

FIG. 3 is a sectional view of an insertion portion of the endoscope according to the first embodiment of the present invention.

FIG. 4 shows a curved structure according to a second embodiment of the present invention;
(A) is its front view, (b) is its side view, (c) is its development view.

FIG. 5 shows a curved structure according to a third embodiment of the present invention;
(A) is the front view, (b) is the development view.

FIG. 6 shows a curved structure according to a fourth embodiment of the present invention;
(A) is its front view, (b) is its side view, (c) is its development view.

FIG. 7 shows a curved structure according to a fifth embodiment of the present invention;
(A) is the front view, (b) is the development view.

FIG. 8 is an explanatory view of a treatment tool for an endoscope.

FIG. 9 is an explanatory view of the use of the endoscope treatment tool.

FIG. 10 is an explanatory view of a biopsy forceps for an endoscope.

FIG. 11 is an explanatory view of basket forceps for an endoscope.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Endoscope, 2 ... Insertion part, 3 ... Operation part, 5 ... Flexible tube, 6
... Bending part, 7 ... Tip, 17 ... Operation wire, 21 ... Bending structure, 22 ... Skin, 23 ... Elastic strip, 24 ... Protrusion, L
₁ … Center axis, L ₂ … Center of rotation.

Claims (1)

(57) [Claims] In a bending portion structure of an endoscope having a curved structure formed by forming an elastic strip in a spiral shape, adjacent strip portions between pitches of the elastic strip are locally brought into contact with each other. A convex portion is provided, and the point of contact becomes a rotation center when performing a bending operation, and a rotation center line connecting the intersections intersects substantially perpendicularly to a central axis direction of the bending structure. Endoscope bending section structure.