JPH05184524A - Bending operation device for flexible tube - Google Patents

Abstract

PURPOSE:To prevent a shape memory member of a bend shape from being twisted, and to surely bend it in a desired direction even if a bending operation is repeated by providing a twist preventing member formed by a flexible material whose hardness is higher than that of a material of a flexible tube on the inside wall surface of an insert-through hole. CONSTITUTION:On a tube wall of a catheter main body 1a, a pair of insert- through holes 3a, 3b are formed along the axis center direction on both sides of a channel 2, respectively. In these insert-through holes 3a, 3b, a pair of roughly plate-like shape memory member 4a, 4b for a bending operation, consisting of the shape memory member deformed by electric conduction heating are inserted through, respectively. Also, on the inside wall surface of the insert- through holes 3a, 3b of the catheter main body 1a, twist preventing members 9a, 9b formed by a flexible material whose hardness is higher than that of a material of the catheter main body 1a are provided. In such a way, the shape memory member of a bend shape can be prevented from being twisted, and it can be bent in a desired direction even if the bending operation is repeated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flexible tube bending operation device for bending a flexible tube in accordance with a deformation operation of a substantially flat plate shape memory member made of a shape memory material.

[0002]

2. Description of the Related Art Conventionally, as a bending operation device for a flexible tube such as an endoscope or a catheter, a substantially flat plate shape memory member formed of a shape memory material such as a shape memory alloy is arranged in the bending portion of the flexible tube. However, there is a configuration in which the bending portion of the flexible tube is bent in accordance with the deformation operation of the shape memory member when the shape memory member is electrically heated.

In this case, an insertion hole for inserting the shape memory member is formed in the tube wall of the flexible tube along the axial direction.
The cross-sectional shape of this insertion hole is formed in a rectangular shape that is substantially the same as the cross-sectional shape of the shape memory member.

The shape memory member is held in a substantially linear basic shape when not energized, and in this state, the bending portion of the flexible tube is held in a substantially linear non-curved shape. When the shape memory member is electrically heated, the shape memory member is curved and deformed into a substantially arc shape, and the bending portion of the shape memory member is bent and the bending portion of the flexible tube is operated. Is becoming

[0005]

In the conventional structure described above, when the bending operation of the flexible tube is repeated, the shape memory member gradually bends in the insertion hole of the flexible tube, and the shape memory member is gradually bent in the insertion hole. There is a problem that the mounting position of the shape memory member is gradually displaced. Therefore, as the number of times the bending operation of the flexible tube is repeated increases, the amount of bending of the shape memory member in the insertion hole also increases, and thus when the shape memory member is heated by energization with such a large amount of bending. Has a problem that the shape memory member is curved in a direction different from a desired direction, and the flexible tube cannot be accurately curved in the direction of the target portion.

The present invention has been made in view of the above circumstances. It is possible to prevent the shape memory member having a bent shape from being twisted, and to reliably bend the shape memory member in a desired direction even if the bending operation is repeated. An object of the present invention is to provide a bending operation device for a flexible tube.

[0007]

According to the present invention, an insertion hole of a substantially flat plate shape memory member made of a shape memory material that is deformed by electric heating is formed in a tube wall of a flexible tube along an axial direction. In a bending operation device for a flexible tube that bends the flexible tube according to a deformation operation of a shape memory member mounted in an insertion hole, a twist formed of a flexible material having a hardness higher than that of the flexible tube. The prevention member is arranged on the inner wall surface of the insertion hole.

[0008]

When the shape memory member is deformed, the torsion preventing member having a high hardness on the inner wall surface of the insertion hole prevents the shape memory member from being twisted in the insertion hole of the flexible tube to mount the shape memory member in the insertion hole. By preventing the displacement of the position, even when the bending operation is repeated, it is possible to bend in the target direction.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to FIGS. FIG. 1 shows a main configuration of a catheter 1 which is a medical tube (flexible tube).
The main body 1a of the catheter 1 is formed of, for example, a polyurethane multi-lumen tube. Although polyurethane is used for the multi-lumen tube of the catheter body 1a, other materials such as silicon and polyethylene may be used.

In addition, as shown in FIG. 2, a channel 2 is formed at the central portion of the catheter body 1a, for example, for feeding or suctioning, or for inserting a small-diameter scope (endoscope), a guide wire or the like. There is. The channel 2 has a substantially oval cross section.

Further, a pair of insertion holes 3a and 3b are formed in the tube wall of the catheter body 1a on both sides of the channel 2 along the axial direction. A pair of substantially flat plate shape memory members 4a and 4b for bending operation, which are made of a shape memory material and are deformed by electric heating, are inserted into the through holes 3a and 3b, respectively.

As the shape memory members 4a and 4b, various shape memory alloy (SMA) materials such as Ti-Ni alloy and Cu-Zn-Al alloy can be used. Among them, Ti-Ni alloy is preferable. ..

Further, the shape memory alloy of each shape memory member 4a, 4b is held in a linear basic shape as shown by a solid line in FIG. Then, as shown by the phantom line in the figure, it is transformed into an arcuate curved shape. Then, when the energization is stopped and the temperature of the shape memory alloy falls below the transformation temperature, the original linear shape is restored. The transformation temperature is preferably set within the range of body temperature or higher and about 50 ° C. or lower, but higher temperatures can be used by combining various cooling and heat insulating means.

The shape memory members 4a and 4b are arranged at the tip of the catheter body 1a. As shown in FIG. 4, one end of each current-carrying wire 5a, 5b is connected to the base end of each shape memory member 4a, 4b. Further, the lead wires 6a, 6 for feedback are provided at the leading ends of the shape memory members 4a, 4b.
One end of b is connected. These return leads 6
As shown in FIG. 2, a and 6b are inserted laterally of the shape memory members 4a and 4b in the insertion holes 3a and 3b.
The energizing wires 5a, 5b and the lead wires 6a,
The other end of 6b passes through the insertion holes 3a and 3b, and the power source 7 in the energization control device provided on the proximal side of the catheter body 1a
And the changeover switch 8.

In this case, an energization amount control unit (not shown) is connected to the energization control device, and the energization amount control unit can arbitrarily control the energization amount of each shape memory member 4a, 4b. Here, each shape memory member 4a, 4
The energization to b is preferably PWM (pulse width modulation) energization. It should be noted that each of the shape memory members 4 is used during the suspension time of the PWM energization.
By detecting the resistance value of the shape memory alloys a and 4b and knowing the temperature change of the shape memory alloy itself, the energization amount can be controlled, and the resistance value control for controlling the bending amount can also be performed.

Further, the insertion hole 3 of the catheter body 1a
Twist prevention members 9a and 9b made of a flexible material having a hardness higher than that of the catheter body 1a, for example, Teflon (trade name of DuPont) are provided on the inner wall surfaces of a and 3b. The cross-sectional shapes of the insertion holes 3a, 3b of the shape memory members 4a, 4b of the catheter body 1a are thin and flat in the bending direction of the catheter body 1a. The structure is such that the catheter body 1a is easily bent only in the bending direction and is hard to bend in the direction perpendicular to the bending direction of the catheter body 1a.

The ends of the shape memory members 4a and 4b on the proximal side are connected to the energizing wires 5a and 5b through the caulking members 10a and 10b, and these caulking members 10 are also connected.
a and 10b allow the insertion hole 3a of the catheter body 1a,
It is fixed to the inner wall surface of 3b.

Further, the tip end openings of the insertion holes 3a, 3b are sealed with sealing portions 11a, 11b made of the same resin as the multi-lumen tube of the catheter body 1a. Further, cavities 12a and 12b are formed at the tip ends of the shape memory members 4a and 4b, and the tip ends of the shape memory members 4a and 4b freely slide along the inner wall surfaces of the insertion holes 3a and 3b. It is possible.

Next, the operation of the above configuration will be described.
First, when observing the inside of the lumen by inserting the endoscope into the channel 2 of the catheter 1 shown in the present embodiment, which is inserted into the lumen of a relatively thin body such as the bile duct, the pancreatic duct or the blood vessel, The distal end of the catheter 1 or the distal end surface of the endoscope comes into contact with the tube wall due to the bending of the lumen or the bending of the catheter 1 or the distal end of the endoscope, or the desired position in the lumen is set at a short distance. It may not be observable.

At this time, in the power control device on the hand side,
By operating the energization of each shape memory member 4a, 4b, an electric current is made to flow through each shape memory member 4a, 4b at the tip of the catheter 1, and each shape memory member 4a, 4b is heated to cause shape recovery. As a result, the tip of the catheter 1 is bent in the direction of the curved shape previously stored in each shape memory member 4a, 4b by the shape recovery force of each shape memory member 4a, 4b.

For example, as shown in FIG.
A duodenoscope 14 is inserted into the duodenum 13 of a patient via a lumen such as the stomach. Subsequently, the catheter 1 is introduced into the body of the patient through the treatment instrument insertion channel of the duodenoscope 14.

The distal end of the introduced catheter 1 is projected outward from the channel opening formed in the distal end portion of the duodenoscope 14, and the distal projection of the catheter 1 is introduced into the common bile duct 15. To do. In addition, 16 is a pancreatic duct.

Here, the shape memory member 4 of the catheter 1
a and 4b are held in a linear basic shape at room temperature and body temperature, and when not energized, the tip of the catheter 1 is held in a linear state by the elastic force of the shape memory alloy of the shape memory members 4a and 4b.

When the distal end of the catheter 1 is oriented in a desired direction, the shape memory members 4a and 4b are electrically heated. Here, for example, when the distal end of the catheter 1 is bent upward as shown in FIG. 4, the shape of the upper shape memory member 4a in FIG. The memory alloy is electrically heated to restore the shape memory member 4a into a bow shape which is a memory shape. At this time, the shape memory alloy of the shape memory member 4a causes the multi-lumen tube of the catheter body 1a to be curved and deformed while sliding in the twist prevention member 9a of the insertion hole 3a of the catheter body 1a.

Further, the amount of electricity supplied to the shape memory member 4a is adjusted by the amount of electricity supplied to the shape memory member 4a in the energization amount control section of the energization controller, so that the amount of bending of the shape memory member 4a is adjusted.
The bending angle of can be arbitrarily determined.

Further, when the distal end portion of the catheter 1 is bent downward in FIG. 4, the shape of the lower shape memory member 4b in FIG. 4 is accompanied by the changeover operation of the changeover switch 8 in the energization control device. The memory alloy is electrically heated to restore the shape memory member 4b into a bow shape which is a memory shape. As a result, the shape memory alloy of the shape memory member 4b causes the multi-lumen tube of the catheter body 1a to be curved and deformed while sliding in the twist prevention member 9b of the insertion hole 3b of the catheter body 1a, and the distal end portion of the catheter 1 is shown in FIG. The bending operation can be performed in the downward direction.

Therefore, in the above-mentioned structure, the twisting preventing members 9a, 9b made of Teflon having a hardness higher than that of the material of the catheter body 1a made of polyurethane.
Is disposed on the inner wall surfaces of the insertion holes 3a and 3b of the catheter body 1a, each shape memory member 4 of the catheter body 1a is
When the a and 4b are deformed, the torsion-preventing members 9a and 9b having high hardness on the inner wall surfaces of the insertion holes 3a and 3b are used to hold the shape memory member 4a in the insertion holes 3a and 3b of the catheter body 1a.
It is possible to prevent the twisting of 4b. for that reason,
Since it is possible to prevent the mounting positions of the shape memory members 4a and 4b in the insertion holes 3a and 3b from being deviated, even when the bending operation is repeated, the catheter body 1a can be prevented.
It is possible to reliably prevent the shape memory alloys of the bent shape memory members 4a and 4b from being twisted, and to bend the distal end portion of the catheter body 1a in the desired direction.

Furthermore, since the twist preventing members 9a and 9b having high hardness on the inner wall surfaces of the insertion holes 3a and 3b are formed of Teflon having a slip property, the shape memory members 4a and 4b are formed.
The sliding resistance of the sliding contact portion between the shape memory alloy and the tube wall surface of the catheter body 1a can be reduced. Therefore, the bending operation of the distal end portion of the catheter body 1a can be smoothly performed.

In the above embodiment, when the distal end of the catheter 1 is bent upward in FIG. 4, the shape memory alloy of the upper shape memory member 4a in FIG. When the memory member 4a is restored to the bow shape which is the memory shape, and when the distal end portion of the catheter 1 is bent downward in FIG. 4, the shape memory alloy of the lower shape memory member 4b in FIG. 4 is energized. Although the structure in which the shape memory member 4b is restored to the bow shape which is the memory shape by heating is shown, conversely, when the distal end portion of the catheter 1 is bent upward in FIG. In the figure, the shape memory alloy of the lower shape memory member 4b is electrically heated to restore the shape memory member 4b to the upward bow shape which is the memory shape, and the tip portion of the catheter 1 is moved downward in FIG. Bending operation Case performs energization heating the shape memory alloy of the upper shape-memory member 4a in the figure, may be configured to restore the shape memory member 4a downward arcuate a memory shape.

Further, as in the second embodiment of the present invention shown in FIG. 6, concave portions 21a, 21b are formed on the inner wall surfaces of the insertion holes 3a, 3b of the catheter body 1a so as to project toward the outer peripheral surface side.
May be provided, and the return lead wires 6a and 6b may be disposed in the recessed portions 21a and 21b.

In this case, the shape memory alloys of the shape memory members 4a and 4b and the catheter body 1a are formed by the recessed portions 21a and 21b which are protruded toward the outer peripheral surface on the inner wall surfaces of the insertion holes 3a and 3b of the catheter body 1a. Since it is possible to reduce the sliding contact area with the tube wall surface of the tube body, the sliding resistance of the sliding contact portion between the shape memory alloy of each shape memory member 4a, 4b and the tube wall surface of the catheter body 1a is further effective. Can be lowered. Therefore, the bending operation of the distal end portion of the catheter body 1a can be smoothly performed.

Furthermore, the concave portions 21 of the insertion holes 3a and 3b
Since the return lead wires 6a and 6b are disposed in the a and 21b, the shape memory members 4a and 4b are provided inside the insertion holes 3a and 3b.
The inside of the catheter body 1a can be used more effectively and the outer diameter of the catheter body 1a can be made smaller than in the case where b and the return lead wires 6a and 6b are arranged side by side.

By applying hydrophilic lubrication treatment to the surface of the shape memory alloy of each shape memory member 4a, 4b, the space between the shape memory alloy of each shape memory member 4a, 4b and the tube wall surface of the catheter body 1a can be improved. The sliding resistance of the sliding contact portion may be reduced.

7 to 9 show the third embodiment of the present invention. This is the shape memory member 31a, 31b arranged at the tip of the catheter 1 shown in FIG.
As shown in (A) and (B), it is formed in a state in which a plurality of thin film shape memory alloys 34 having a remembered curved shape are laminated.

In this case, each shape memory member 31a, 31b
Lead wires 32, 33 for energization are connected to both ends of the. These lead wires 32, 33 extend to the proximal side of the catheter 1 and are connected to an energization control device provided on the proximal side, and the shape memory member 31 is connected by the energization control device.
A and 31b can be selectively energized and heated.

In addition, each shape memory member 31a having a multilayer structure,
At least two or more 31b are arranged to face the tip of the catheter body 1a. Then, each shape memory member 31
The shape memory alloys 34 ... Of a, 31b are held in a linear state at room temperature or body temperature, and the distal end portion of the catheter 1 is held in a linear state.

Further, in the insertion holes 3a, 3b at the tip of the catheter body 1a, a Teflon tube for preventing the shape memory members 31a, 31b from being twisted at the time of bending at the portions corresponding to the shape memory members 31a, 31b. (Twist prevention member)
35a and 35b are arranged.

Therefore, even in the case of the above structure, the Teflon tubes 35a and 35b having a hardness higher than that of the material of the catheter main body 1a made of polyurethane correspond to the shape memory members 31a and 31b in the insertion holes 3a and 3b. Since the shape memory members 31a, 31b of the catheter body 1a are deformed, the Teflon tubes 35a, 35b having a high hardness on the inner wall surfaces of the insertion holes 3a, 3b are used in the insertion holes 3a, 3b of the catheter body 1a. It is possible to prevent the shape memory members 31a and 31b from being twisted. Therefore, it is possible to prevent the mounting positions of the shape memory members 31a and 31b in the insertion holes 3a and 3b from being deviated, so that each shape memory member of the bent shape of the catheter body 1a can be repeated even when the bending operation is repeated. 31
It is possible to reliably prevent the shape memory alloys of a and 31b from being twisted, and it is possible to correctly bend and operate the distal end portion of the catheter body 1a in the target direction.

Further, when the distal end portion of the catheter body 1a is bent, the shape memory alloys 34 of the shape memory members 31a and 31b having a multi-layered structure are independently slid in the axial direction of the catheter body 1a to recover the shape. Wake up. Therefore, compared with the shape memory members 4a and 4b of the first embodiment formed of a single shape memory alloy instead of the multilayer structure, when the same tip bending angle of the catheter 1 is obtained, the shape memory alloy material is used. There is little apparent distortion that occurs in the.

That is, if the strain amount of the shape memory alloy material due to the deformation of the catheter 1, that is, the bending operation, is the same, the catheter 1 provided with the shape memory alloys 34 having a multilayer structure.
A larger bending amount can be obtained. as a result,
It is possible to reduce the energization amount of each shape memory member 31a, 31b during the bending operation, and at the same time, each shape memory member 31.
The amount of heat generated by a and 31b can also be reduced, and the safety for the living body can be improved.

In order to reduce the sliding friction between the multilayer shape memory alloys 34, a resin film such as Teflon is coated between the shape memory alloys 34, or a powdery solid lubricant is interposed. It may be configured to.

Further, as in the fourth embodiment shown in FIG. 10 and the fifth embodiment shown in FIG. 11, each shape memory member 31 is used.
By changing the axial length of the multilayer shape memory alloys 34 ... Of a and 31b for each film, the flexibility of the distal end portion of the catheter 1 is changed, and the insertability of the catheter 1 is improved. May be improved.

12 and 13 show a sixth embodiment of the present invention. This is an application of the present invention to the insertion portion 42 of the endoscope 41 as a medical tube (flexible tube).

That is, the main body 42a of the insertion portion 42 of the endoscope 41 of this embodiment is formed of a multi-lumen tube made of polyurethane. This insert body 4
As shown in FIG. 13, an image guide insertion hole 43, a pair of light guide insertion holes 44a and 44b, a treatment instrument insertion channel 45, and a pair of insertion holes 46a and 4 are provided on the tube wall of 2a.
6b are formed in parallel along the axial direction of the insertion portion main body 42a.

An image guide fiber 47 is provided in the image guide insertion hole 43 of the insertion portion main body 42a as shown in FIG. 12, and an objective lens 48 and the like are attached to the tip of the image guide fiber 47. .. Further, the light guide insertion hole 44 of the insertion portion main body 42a
Light guide fibers 49a and 49b are provided in a and 44b.
Are arranged.

The base end of the image guide fiber 47 is extended to the proximal side of the endoscope 41, is connected to the eyepiece, and is connected to the light guide fibers 49a, 49.
The proximal end portion of b is connected to the light source device located outside from the proximal side of the endoscope 41.

Further, the insertion holes 46a of the insertion portion main body 42a,
A pair of substantially flat plate shape memory members 50a and 50b for bending operation, which are made of a shape memory alloy (SMA) material and which are deformed by electric heating, are inserted into the tip end portion 46b.

The shape memory alloy of each shape memory member 50a, 50b is maintained in a linear basic shape in the non-energized state, and is deformed into a bent shape that bends in an arc when heated by electricity. Further, as shown in FIG. 12, one ends of energizing wires 51a and 51b are connected to the base ends of the shape memory members 50a and 50b. Furthermore, each shape memory member 50a,
One end of the return lead wires 52a and 52b is connected to the leading end of 50b. Then, the current-carrying wires 51a, 5
1b and the other end of each of the lead wires 52a and 52b are provided with an insertion hole 4
It is connected to an energization control device provided on the hand side of the insertion portion main body 42a through 6a and 46b.

Further, the insertion hole 46 of the insertion portion main body 42a
Twist prevention members 53a and 53b made of Teflon (trade name of DuPont) having a hardness higher than that of the material of the insertion portion main body 42a are provided on the inner wall surfaces of the a and 46b. In addition, each shape memory member 50a of the insertion portion main body 42a,
The cross-sectional shape of the insertion holes 46a, 46b of the insertion hole 50b is thin in the bending direction of the insertion portion main body 42a, and is long and flat in the direction perpendicular to the bending direction.
It is formed in a structure in which it is easy to bend only in the bending direction, and is hard to bend in the direction perpendicular to the bending direction of the insertion portion main body 42a.

Further, the ends of the shape memory members 50a and 50b on the proximal side are connected to the current-carrying wires 51a and 51b through the caulking members 54a and 54b, and the caulking members 54a and 54b are used to insert the insertion portion main body 42a. It is fixed to the inner wall surfaces of the insertion holes 46a and 46b.

Further, the distal end opening portions of the insertion holes 46a and 46b are sealed with sealing portions 55a and 55b made of the same resin as the multi-lumen tube of the insertion portion main body 42a. Further, cavities 56a and 56b are formed at the tip ends of the shape memory members 50a and 50b, and the tip ends of the shape memory members 50a and 50b are inserted into the insertion holes 46a and 46b.
It is freely slidable along the inner wall surface of b.

When the distal end portion of the insertion portion main body 42a is oriented in a desired direction, the shape memory members 50a and 50b are respectively.
To heat. At this time, one of the upper and lower shape memory members 50a and 50b in FIG. 12 is electrically heated to restore the shape memory member on the electrically heated side, for example, 50a, to the upward bow shape in FIG. 12, which is the memory shape. .. At this time, the shape memory alloy of the shape memory member 50a causes the multi-lumen tube of the insertion portion main body 42a to be curved and deformed while sliding in the twist prevention member 53a of the insertion hole 46a of the insertion portion main body 42a.

Furthermore, by adjusting the amount of electricity supplied to the shape memory member 50a by the electricity supply control device, the amount of bending of the shape memory member 50a can be adjusted, and the bending angle of the insertion portion main body 42a can be arbitrarily determined.

Incidentally, by electrically heating the other shape memory member 50b, this shape memory member 50b is restored to the downward bow shape in FIG. 12, which is the memory shape. At this time, the shape memory alloy of the shape memory member 50b is inserted into the insertion portion main body 4
The multi-lumen tube of the insertion portion main body 42a is curved and deformed while sliding in the twist prevention member 53b of the insertion hole 46b of 2a.

Therefore, in the above structure, the twist preventing members 53a, 53 made of Teflon having a hardness higher than that of the material of the insertion portion main body 42a made of polyurethane.
Since b is disposed on the inner wall surfaces of the insertion holes 46a and 46b of the insertion portion main body 42a, each shape memory member 5 of the insertion portion main body 42a is formed.
0a, 50b prevents deformation of the shape memory members 50a, 50b in the insertion holes 46a, 46b of the insertion portion main body 42a by the torsion preventing members 53a, 53b having high hardness on the inner wall surfaces of the insertion holes 46a, 46b. be able to. Therefore, it is possible to prevent the mounting positions of the shape memory members 50a and 50b in the insertion holes 46a and 46b from deviating from each other. Therefore, even when the bending operation is repeated, each shape memory of the bending shape of the insertion portion main body 42a is performed. The bending of the shape memory alloy of the members 50a and 50b can be reliably prevented, and the distal end portion of the insertion portion main body 42a can be correctly bent in the target direction.

Furthermore, since the twist preventing members 53a and 53b having high hardness on the inner wall surfaces of the insertion holes 46a and 46b are made of Teflon having a slip property, each shape memory member 5 is formed.
The sliding resistance of the sliding contact portion between the shape memory alloys 0a and 50b and the tube wall surface of the insertion portion main body 42a can be reduced, and the bending operation of the distal end portion of the insertion portion main body 42a can be performed smoothly.

The present invention is not limited to the above embodiments. For example, the twist-preventing members 9a and 9b having high hardness that prevent twisting may not only surround the entire shape memory members 4a and 4b of the catheter body 1a but may be partial.

For example, the anti-twist members 9a and 9b are provided only at both ends of the shape memory members 4a and 4b, or the anti-twist members 9a and 9b are provided at approximately half of the shape memory members 4a and 4b in the axial direction. 9b may be provided, and further, the twist preventing members 9a and 9b may be provided at substantially central portions in the axial direction of the shape memory members 4a and 4b.

Further, the shape memory member 4 having a circular cross section.
Alternatively, the a and 4b may be locally provided with a rectangular cross section, and the twist prevention members 9a and 9b may be arranged in the rectangular cross section. Furthermore, it goes without saying that various modifications can be made without departing from the scope of the present invention.

[0060]

According to the present invention, since the anti-twist member formed of a flexible material having a hardness higher than that of the flexible tube is disposed on the inner wall surface of the insertion hole, the shape memory member having a bent shape can be formed. Bending can be prevented, and even if the bending operation is repeated, it can be surely bent in a desired direction.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view showing a schematic configuration of a main part of a catheter tip according to a first embodiment of the present invention.

FIG. 2 is a transverse cross-sectional view of a main part showing a mounted state of a twist prevention member.

FIG. 3 is a side view showing a curved deformation state of the shape memory member of the catheter.

FIG. 4 is a schematic configuration diagram showing an electric wiring state of a shape memory member of a catheter.

FIG. 5 is a schematic configuration diagram showing a usage state of a catheter.

FIG. 6 is a cross-sectional view of the essential parts showing the second embodiment of the present invention.

FIG. 7 is a schematic configuration diagram showing a third embodiment of the present invention.

FIG. 8 is a perspective view showing a connection state between a shape memory member and a lead wire according to a third embodiment.

9A is a vertical sectional view showing a basic shape of a shape memory member, and FIG. 9B is a vertical sectional view showing a deformed state of the shape memory member.

FIG. 10 is a vertical cross-sectional view of a main part showing a fourth embodiment of the present invention.

FIG. 11 is a vertical cross-sectional view of the essential parts showing the fifth embodiment of the present invention.

FIG. 12 is a vertical cross-sectional view of a main part showing a sixth embodiment of the present invention.

FIG. 13 is a transverse cross-sectional view of the main parts of the endoscope of the sixth embodiment.

[Explanation of symbols]

1 ... Catheter (flexible tube), 3a, 3b, 46a, 46
b ... insertion hole, 4a, 4b, 31a, 31b, 50a, 5
0b ... Shape memory member, 9a, 9b, 53a, 53b ... Twisting prevention member, 35a, 35b ... Teflon tube (twisting prevention member), 42 ... Endoscope insertion part (flexible tube).

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Hideyuki Adachi Inventor Hideyuki Adachi 2-43-2 Hatagaya, Shibuya-ku, Tokyo Inside Olympus Optical Co., Ltd. (72) Inventor Yasuo Hirata 2-43-2 Hatagaya, Shibuya-ku, Tokyo Olympus Optical Co., Ltd.

Claims (1)

[Claims] 1. An insertion hole of a substantially flat plate shape memory member made of a shape memory material that is deformed by electric heating is formed in a tube wall of a flexible tube along an axial direction, and a shape attached to the insertion hole. In a bending operation device for a flexible tube that bends the flexible tube according to a deformation operation of a memory member, a twist prevention member formed of a flexible material having a hardness higher than that of the flexible tube is provided in the insertion hole. A bending operation device for a flexible tube, which is arranged on an inner wall surface.