JP4017736B2 - Endoscope insertion part - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an insertion portion of an endoscope that is inserted into a body cavity or the like.
[0002]
[Prior art]
The insertion part of the so-called flexible endoscope is constructed by inserting and placing a built-in object such as an optical fiber bundle into the exterior flexible tube, but the portion near the tip is relatively free along the shape of the organ in the body cavity. It is necessary to form it flexibly so that it bends, and to make the portion on the hand side stiff so that a delicate push-pull operation performed by the operator is transmitted to the tip side.
[0003]
Therefore, conventionally, the flexibility of the exterior flexible tube itself has been changed in the middle by changing the thickness, hardness, and the like of the outermost synthetic resin skin of the exterior flexible tube depending on the position.
[0004]
[Problems to be solved by the invention]
The outermost synthetic resin outer sheath of the outer flexible tube is generally formed by extrusion molding. However, in the manufacturing method in which the thickness and hardness of the outer flexible tube are changed halfway, it takes considerable time and cost to manufacture the outer flexible tube. . In addition, when the molding conditions are changed in the middle, there are many cases where variations in flexibility occur between products due to variations in the molding conditions.
[0005]
Accordingly, an object of the present invention is to provide an insertion portion of an endoscope in which the flexibility is easily and smoothly changed without changing the thickness or hardness of the outer skin of the flexible tube.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, the insertion portion of the endoscope of the present invention has an operation wire that bends the bending portion by connecting a bending portion that is bent by remote operation to a distal end of a flexible tube that covers the insertion portion. In order to insert and guide the wire guide, the distal end portion of the wire guide inserted through the entire length of the flexible tube is fixed to the distal end portion of the flexible tube. A wound coil pipe and a superelastic alloy pipe are connected in series, and the tightly wound coil pipe portion is disposed in a range near the tip of the flexible tube, and the superelastic alloy pipe portion is placed in the deformable portion. It arrange | positions in the range near the base end of a flexible tube, It is characterized by the above-mentioned.
[0007]
The superelastic alloy pipe may be fitted and joined to the outer periphery of the tightly wound coil pipe at the connecting portion between the tightly wound coil pipe and the superelastic alloy pipe. The outer periphery of the end of the coil pipe may be ground, and the superelastic alloy pipe may be fitted there.
[0008]
Further, at the connecting portion between the tightly wound coil pipe and the superelastic alloy pipe, the end face of the tightly wound coil pipe and the end face of the superelastic alloy pipe are in contact with each other and straddle both outer surfaces. Both of them may be fixed to the connection pipe fitted in this case, and in that case, the inner surface of the end of the superelastic alloy pipe on the side of the connecting part is formed in a tapered shape that gradually spreads toward the mouth side. Also good.
[0009]
Further, a plurality of the wire guides are inserted and arranged in parallel in the flexible tube, and the connecting portion of the tightly wound coil pipe and the superelastic alloy pipe is arranged with the position shifted in the longitudinal direction for each wire guide. May be.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described with reference to the drawings.
FIG. 2 shows an endoscope. An insertion portion to be inserted into a body cavity or the like has a bending portion 3 which is bent by a remote operation from the operation portion 1 at a distal end of a soft portion covered with a flexible tube 2. The distal end body 4 having a built-in objective optical system and the like is coupled to the distal end of the curved portion 3.
[0011]
The flexible tube 2 is configured, for example, by covering a spiral tube made of a metal strip with a mesh tube and covering the outer surface thereof with a skin such as polyurethane resin. The outer skin portion covering the flexible tube 2 may have any structure, but it is not necessary to change the flexibility or flexibility of the flexible tube 2 itself by changing the thickness or hardness of the outer skin. .
[0012]
Inside the flexible tube 2 and the bending portion 3, a flexible built-in object whose distal end is connected to the distal end body 4 such as a treatment instrument insertion channel, an optical fiber bundle, and various tubes is inserted over the entire length. Has been placed.
[0013]
An observation window 5 for introducing an observation image into the objective optical system, an illumination window 6 for emitting illumination light toward the observation field, a treatment instrument insertion channel outlet 7a, and illustration are omitted on the surface of the distal end main body 4. An air supply / water supply nozzle and the like are arranged.
[0014]
The operation section 1 connected to the base end of the flexible tube 2 is provided with bending operation knobs 8 a and 8 b for bending the bending section 3. The bending portion 3 can be bent in any direction by pulling the operation wire and pulling the left or right operation wire with the left / right bending operation knob 8b.
[0015]
In addition, an air / water supply operation button 11, a suction operation button 12, a treatment instrument insertion port 7b, and the like are disposed in the operation unit 1. A light guide cable 14 is connected to a light source device (not shown).
[0016]
FIG. 1 shows a flexible tube 2 portion of the insertion portion. The flexible tube 2 has an outer diameter of about 5 to 15 mm and a length of about 50 to 150 cm. However, for the sake of easy understanding, the flexible tube 2 is shown to be thicker and shorter than actual.
[0017]
A proximal end connection base 21 for connecting to the operation unit 1 is attached to the proximal end portion of the flexible tube 2, and a distal end connection cylinder 22 for connecting the bending portion 3 to the distal end portion of the flexible tube 2. Is attached.
[0018]
Reference numeral 23 denotes a bending operation wire for remotely operating the bending portion 3, the distal end of which is connected to the distal end portion of the bending portion 3, and the proximal end of the operation portion 1 by rotating the bending operation knobs 8 a and 8 b. It is pulled by the bending operation mechanism arranged inside.
[0019]
A wire guide 24 that guides the bending operation wire 23 so as to advance and retreat in the axial direction is formed by connecting a front-side tightly wound coil pipe 24a and a base-side superelastic alloy pipe 24b in series.
[0020]
The tightly wound coil pipe 24a is formed by tightly winding a stainless steel wire with a constant diameter, and is very flexible. On the other hand, the superelastic metal is, for example, a Ti—Ni (titanium-nickel) type, and the elastic limit of the metal is very large.
[0021]
As a result, the superelastic alloy pipe 24b does not plastically deform even if it is bent with a radius of curvature that allows the flexible tube 2 to be bent, and has a resilience to return to the original straight state. The resilience is greater than the tightly wound coil pipe 24a.
[0022]
The tip of the tightly wound coil pipe 24a of the wire guide 24 is fixed to the inner peripheral surface of the tip connecting cylinder 22 by spot welding or silver brazing at 90 ° intervals as shown in FIG. FIG. 1 shows two sets of four sets of bending operation wires 23 and wire guides 24.
[0023]
The base end portion of the superelastic alloy pipe 24 b of the wire guide 24 is fixed to the frame of the bending operation mechanism in the operation unit 1. Portions other than both ends of the wire guide 24 are inserted into the flexible tube 2 in a free state.
[0024]
FIG. 4 shows a connecting portion between the tightly wound coil pipe 24a and the superelastic alloy pipe 24b of the wire guide 24. The outer peripheral surface of the proximal end portion of the tightly wound coil pipe 24a is ground and thinned. The inner surface of the superelastic alloy pipe 24b is fitted and joined.
[0028]
With such a configuration, in the portion near the base end of the flexible tube 2 in which the wire guide 24 is composed of the superelastic alloy pipe 24b, the superelastic alloy pipe 24b becomes a resistance when the flexible tube 2 is bent. The flexibility is suppressed by acting, and the push-pull operation of the flexible tube 2 is easily transmitted to the distal end side.
[0029]
On the other hand, the portion near the tip of the flexible tube 2 in which the wire guide 24 is composed of the closely wound coil pipe 24a has a low resistance to the bending operation of the flexible tube 2, and thus has a high flexibility (that is, flexibility). Rich) and deforms smoothly along the shape of the organ in the body cavity.
[0030]
As a configuration, the tightly wound coil pipe 24a and the superelastic alloy pipe 24b are simply connected in series to form the wire guide 24, so that no special space is required.
[0031]
Further, as shown in FIG. 1, if the connecting portion between the closely wound coil pipe 24a and the superelastic alloy pipe 24b of each wire guide 24 is shifted in the longitudinal direction, the flexible tube 2 can be used within that range. Flexibility can be gradually and smoothly changed.
[0032]
【The invention's effect】
According to the present invention, the wire guide for inserting and guiding the bending operation wire is formed by connecting the closely wound coil pipe and the superelastic alloy pipe in series, and the closely wound coil pipe portion is located near the tip of the flexible tube. By placing the pipe part made of superelastic alloy in the range near the base end of the flexible tube, it was covered with the flexible tube without changing the thickness or hardness of the outer skin of the flexible tube. The flexibility of the part can be easily changed in the middle without any variation between products, and no special space is required.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a surface including a tube axis of a flexible tube portion according to an embodiment of the present invention.
FIG. 2 is a schematic external view showing the overall configuration of the endoscope according to the embodiment of the present invention.
3 is a sectional view taken along line III-III in FIG.
FIG. 4 is an enlarged cross-sectional view of a connecting portion of the wire guide according to the embodiment of the present invention.
[Explanation of symbols]
2 Flexible tube 3 Bending portion 23 Bending operation wire 24 Wire guide 24a Close-coiled coil pipe 24b Superelastic alloy pipe

Claims (3)

A bending portion that is bent by remote operation is connected to the distal end of the flexible tube that sheathes the insertion portion, and is inserted through the entire length of the flexible tube to guide the operation wire that bends the bending portion. In the insertion portion of the endoscope in which the distal end portion of the wire guide is fixed to the distal end portion of the flexible tube,
The wire guide is formed by connecting a close-coiled coil pipe and a superelastic alloy pipe in series, and the close-coiled coil pipe portion is disposed in a range near the tip of the flexible tube, and the superelastic alloy A pipe part is arranged in a range near the base end of the flexible tube ,
An insertion portion of an endoscope, wherein the superelastic alloy pipe is fitted and joined to an outer periphery of the tightly wound coil pipe at a connection portion between the tightly wound coil pipe and the superelastic alloy pipe. . The outer periphery of an end portion of the tightly wound coil pipe is being ground, which the insertion portion of the endoscope according to claim 1, wherein said superelastic alloy pipe is fitted on. A plurality of the wire guides are inserted and arranged in parallel in the flexible tube, and a connecting portion between the tightly wound coil pipe and the superelastic alloy pipe is arranged with a position shifted in the longitudinal direction for each wire guide. The endoscope insertion portion according to claim 1.

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