JP3135134B2 - Flexible tube bending device - 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 device for a flexible tube used by being inserted into a living body cavity, such as a catheter, an endoscope, a laser probe, or the like.

[0002]

2. Description of the Related Art For example, many insertion tools such as medical catheters and endoscopes are provided with a bending device for bending a distal end portion of an insertion portion. One end of an angle wire for bending operation is fixed to a distal end of an insertion portion inserted into a body cavity as a bending device of this type, and the other end of the angle wire is provided on a proximal operation portion such as an operation knob. There is known a configuration in which the distal end of the insertion portion is bent by connecting the pulley to an operation mechanism or the like and pulling the angle wire in accordance with the operation of the operation knob.

[0003] For example, Japanese Patent Application Laid-Open No. 59-97115 discloses a coil-shaped expansion and contraction made of a shape memory alloy at the distal end of an insertion portion of an insertion tool such as an endoscope and the like. There is shown a bending mechanism for providing a flexible drive member and bending the distal end of an insertion portion of an insertion tool such as an endoscope in accordance with the expansion and contraction operation of the stretchable drive member.

In Japanese Utility Model Laid-Open No. 1-95901, a pair of wires made of a shape memory alloy and extending in the axial direction of the insertion portion are provided at the distal end of the insertion portion of an insertion tool such as an endoscope. A bending mechanism having a structure in which one wire is provided with superelasticity and the other wire has a curved shape such as an inverted J-shape memorized by heat treatment or the like, and these wires are covered with a close-contact coil spring for heat insulation. Have been.

[0005] In this case, at room temperature, the shape memory wire is held in a linearly deformed state by the superelastic force of the superelastic wire and the elastic force of the close coil spring for heat insulation.
The distal end of the insertion portion is held in a linear shape, and the wires are automatically heated and heated so that the shape memory wire is automatically deformed into a previously stored curved shape. In a bending direction.

[0006] By the way, in a bending device configured to bend the distal end side of the insertion portion in accordance with the pulling operation of the angle wire, for example, when the outer diameter of the insertion portion is small as in a blood vessel endoscope, the angle wire is used. In many cases, a curved tube or the like for guiding the towing operation is not provided. for that reason,
For example, when the insertion portion of the insertion tool is inserted into the body cavity, and the insertion portion is bent in accordance with the shape of the body cavity, the angle wire meanders, so that accurate bending operation may be difficult.

Further, Japanese Patent Application Laid-Open No. 59-97115 and Japanese Utility Model Application Laid-Open No. 1-95
In the case of a bending mechanism using a shape memory alloy as disclosed in Japanese Patent Publication No. 901, a space is provided between a stretchable driving member or a shape memory wire and a hand-side component such as an operation switch or a power supply provided on the hand side. Since it is connected via the lead wire, it is possible to prevent the bending operation from becoming difficult as in a bending mechanism using an angle wire even when the insertion portion is bent in accordance with the shape of the body cavity or the like.

However, in the case of the bending mechanism disclosed in JP-A-59-97115, since a coil-shaped elastic driving member is used, there is a problem that the diameter of the entire bending mechanism is increased and the configuration is complicated. Was.

Further, in the case of the bending mechanism disclosed in Japanese Utility Model Application Laid-Open No. 1-95901, the shape memory wire stores a curved shape such as an inverted J-shape by heat treatment or the like. Is configured to bend the distal end of the insertion section in the direction of deformation of the shape memory wire in accordance with the operation of deforming the distal end of the insertion portion into a curved shape stored in advance. Requires a relatively large operating force, and when the operating force of the shape memory wire is small, there is a problem that the distal end portion of the insertion portion cannot be accurately bent to a predetermined shape.

Therefore, in order to solve the above-mentioned problem, for example, as shown in Japanese Patent Application No. 1-225607, a flexible porous tube is formed into a linear shape which contracts and expands in response to a temperature change. A bending operation device has been developed in which a bending operation wire made of a memory alloy is attached along the axial direction of the tube, an energization lead is connected to the bending operation wire, and an energization amount control unit is connected to the other end of the lead. Was done.

[0011]

[Problems to be solved by the invention] However, Japanese Patent Application No. 1-22
In the bending operation device shown in No. 5607, a perforated tube having a length corresponding to the length of the bending operation wire made of a shape memory alloy was bent. For this reason, if the length of the curved portion in the tube axis direction is reduced, the overall length of the bending operation wire is also reduced, and the amount of contraction of the bending operation wire during energization and heating is reduced. It will be less.

Further, if the total length of the bending operation wire is increased in order to increase the bending amount of the tube and the amount of contraction during energization heating is increased, the length of the bent portion in the tube axis direction also increases.

[0013] In the case of insertion into a body cavity having a relatively small lumen diameter and a meandering shape in either case, a short bending portion having a small amount of bending or a long bending portion having a large amount of bending. Operability is poor, and in some cases the insertion operation may not be possible.

The present invention has been made in view of the above circumstances, and an object of the present invention is to obtain a large amount of bending with a short bending portion length so that a lumen having a small lumen diameter can be inserted into a meandering body cavity. It is an object of the present invention to provide a flexible tube bending device that can easily insert a flexible tube.

[0015]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a bending operation wire made of a linear shape memory alloy whose length contracts and expands in accordance with a temperature change in an axial direction of a flexible tube. And bending the outer diameter of the flexible tube at the portion where the bending operation wire is provided by bending the flexible tube.
Partially covered with a tube having a hardness higher than the hardness
The hardness of the covering portion of the flexible tube is higher than that of the other portion .

[0016]

[Function] When the bending operation wire is heated, for example, by energizing,
The bending operation wire contracts and the flexible tube bends. However, since a portion of the flexible tube where the bending operation wire is provided has a portion higher in hardness than other portions, the hardness is increased. A large amount of bending can be obtained in the portion of the flexible tube that deviates from the high portion.

[0017]

Embodiments of the present invention will be described below with reference to the drawings.

1 to 3 show a first embodiment.
1 and 2 show the distal end of a medical catheter 1 as a flexible tube, and FIG. 3 shows the entire catheter 1. The catheter 1 includes a base end 3 having an insertion opening 2 and an insertion portion 5 having a distal end curved portion 4.

A bifurcation 6 is provided at the proximal end 3 of the catheter 1, and a lead wire 7 connected to the insertion unit 5 via this bifurcation 6 is provided. The lead wire 7 is connected to a controller box 8, and the controller box 8 has a joystick 9 for inputting an operation signal.
Is connected.

The insertion section 5 of the catheter 1 is formed by a porous tube 10 made of a flexible resin material such as silicon. That is, the catheter 1 is provided with a channel 11 formed of a large-diameter eccentric hole, and a thick portion 12 formed by providing the channel 11 has two wire insertion holes 12 parallel to the channel 11. 12
Is provided.

A bending operation wire 13 is inserted into the wire insertion holes 12, 12 located in the distal bending portion 4. The bending operation wire 13 is folded back from a substantially middle portion in the longitudinal direction, and both ends are inserted into the wire insertion holes 12, 12, and the folded portion 13 a is fixed to the distal end surface of the distal bending portion 4.

The end of the bending operation wire 13 inserted into the wire insertion holes 12, 12 extends to the base end side of the distal bending portion 4. In addition, the wire insertion hole 12 of the insertion portion 5,
The lead wire 7 inserted into the extension 12 extends to the proximal end side of the distal bending portion 4, and the distal end of the lead wire 7 and the end of the bending operation wire 13 are formed by a ring-shaped caulking member. They are connected by connecting members 14 and 14.

Therefore, the distal curved portion 4 of the catheter 1
The bending operation wire 13 arranged in the axial direction is electrically connected to the controller box 8 via a lead wire 7.

An eccentric hole 1 is provided at the tip of the catheter 1.
A cap 16 having an opening 15 corresponding to 1 is attached, and covers the folded portion 13a of the bending operation wire 13 from the outside in a sealed state.

Further, a part of the distal bending portion 4 provided with the bending operation wire 13 is covered with a heat-shrinkable tube 17 having higher hardness than the porous tube 10. That is, the proximal end side of the distal end curved portion 4 from the substantially middle portion in the longitudinal direction is covered with the heat shrinkable tube 17, and the distal end side is the porous tube 10.
Is in an exposed state.

The bending operation wire 13 is formed of a linear shape memory alloy. That is, for example, in the process of heating from a relatively low temperature of 37 ° C. or lower, which is the body temperature, to a relatively high temperature of the body temperature or more, the length in the axial direction contracts by a certain amount, and the low temperature of the body temperature or lower from the high temperature side A two-way storage process is performed to extend to return to the original length when cooled to the side.

Therefore, when the bending operation wire 13 is incorporated into the perforated tube 10 eccentrically with respect to the center axis of the perforated tube 10 as described above, the bending angle is determined by the inserted bending operation wire 13. Is determined depending on the amount of contraction determined by the length of the bending operation wire, but if the bending operation wire 13 is disposed on a curved portion having a short length by the same length as the length of the curved portion, the heating of the bending operation wire 13 is prevented. Is relatively small, the bending angle of the distal end bending portion 4 is also small, and there is a possibility that the insertability into a body cavity or the like may not be improved.

Further, if the length of the bending operation wire 13 is increased and the length of the curved portion is increased, the bending angle of the distal bending portion 4 is increased by the contraction of the long bending operation wire 13, but the bending angle is small. And so on, and as a result, the insertability is not improved.

In the configuration of the embodiment described above, the length of the curved perforated tube 10 in the axial direction is regulated by the heat-shrinkable tube 17, so that the length is relatively short. Since the operation wire 13 is disposed longer than the length of the curved portion, the amount of contraction due to heating is large, and the contraction causes the bending operation wire 13 to advance and retreat in the perforated tube 10, thereby causing the perforated tube at the distal end curved portion 4 to move. The movement relative to 10 is large, so that the bending angle of the distal bending portion 4 becomes large. Therefore, the bending operation can be reliably performed in a thin lumen such as a body cavity, and the operability is improved.

Therefore, when the insertion section 5 of the catheter 1 is inserted into a body cavity through an insertion channel of an endoscope (not shown), for example, when it is bent like an insertion into a bile duct or the like, or branched in the middle. By manipulating the joystick 9 provided on the hand side, the distal bending portion 4 of the catheter 1 is operated to bend, and inserted according to the bending of the lumen, or selectively advances to a target site in a branch. Let

When a treatment tool such as a biopsy forceps (not shown) is inserted into the channel 11 of the catheter 1 to grasp a lesion in the lumen, the bending section 4 of the catheter 1 is operated to bend. In addition, the treatment can be easily and quickly performed by securely bringing the tip grasping portion of the biopsy forceps to the lesion.

FIGS. 4 and 5 show a second embodiment of the present invention, in which the distal end side of the distal curved portion 4 of the catheter 1 is covered with a heat-shrinkable tube 17 from a substantially middle portion in the longitudinal direction. The side is in a state where the porous tube 10 is exposed. With this configuration, the bending portion is shortened, and the bending operation wire 13 is longer than the bending portion.
May increase the angle of curvature.

FIGS. 6 and 7 show a third embodiment. As in the first embodiment, the insertion section 5 of the catheter 1 has a porous tube 10 made of a flexible resin material such as silicon.
A bending operation wire 13 made of a shape memory alloy is inserted through the porous tube 10.

A coil sheath 18 made of a densely wound metal wire coil having a higher hardness than the porous tube 10 is fitted around the outer periphery of the porous tube 10 so as to be able to advance and retreat in the axial direction. The coil sheath 18 is configured to be able to advance and retreat with respect to the perforated tube 10 on the proximal side of the catheter 1, and the tip of the coil sheath 18 is usually located at a portion where the bending operation wire 13 provided on the perforated tube 10 is provided. ing.

When the catheter 1 thus constructed is inserted into a body cavity, as shown in FIG. 7 (a), when the catheter 1 is bent in a relatively thin lumen 19, the coil sheath 18 is advanced and inserted. The tip bending portion 4 of the portion 5 is shortened.

As shown in FIG. 3B, when the bending operation is performed in the relatively large lumen 20, the coil sheath 1 is used.
8 is retracted to make the distal end curved portion 4 longer. This allows smooth passage of a branch portion with different lumen diameters, treatment of a tube wall, and the like.

Further, as shown in FIG. 3C, when the stenotic lumen 21 or the tube diameter is small and the tube wall is very soft, it is difficult to insert the flexible insertion portion 5 by pushing. By advancing the coil sheath 18 to the distal end of the distal end curved portion 4 of the insertion portion 5, insertion can be performed while pushing and expanding the lumen 21 at the distal end of the coil sheath 18.

FIG. 8 shows a fourth embodiment, and FIG.
Similarly to the embodiment, the insertion portion 5 of the catheter 1 is formed by a perforated tube 10 made of a flexible resin material such as silicon, and a bending operation wire 13 made of a shape memory alloy is inserted through this perforated tube 10. ing. Further, a perforated tube 10 is provided around the perimeter of the perforated tube 10.
Coil sheath 22 made of metal mesh having higher hardness
Are fitted so as to be able to advance and retreat in the axial direction. The method of using the catheter 1 of this embodiment is the same as that of the third embodiment, and a description thereof will be omitted.

FIGS. 9 and 10 show a fifth embodiment.
The insertion section 5 of the catheter 1 is formed by a porous tube 10 made of a flexible resin material such as silicon. That is, a large-diameter channel 23 is provided at the axis of the catheter 1.
Are provided, and two wire insertion holes 24 are provided symmetrically with respect to the central axis of the channel 23.

The bending operation wire 1 made of a shape memory alloy is inserted into the wire insertion holes 24, 24 located in the tip bending portion 4.
3 and 13 are respectively inserted. Bending operation wire 1
3 is folded back from a substantially middle portion in the longitudinal direction, and both end sides thereof are inserted into the wire insertion holes 24, 24, and the folded back portion 13 is formed.
“a” is fixed to the distal end surface of the distal end bending portion 4. And
The insertion section 5 can be bent in two directions by independently heating the bending operation wires 13 and 13.

A perforated tube 10 is provided on the outer periphery of the distal bending portion 4 at the portion where the bending operation wires 13 are provided.
A polyethylene tube 25 made of, for example, polyethylene having a higher hardness is fitted.

The polyethylene tube 25 has two distal bending portions 4-2 due to the contraction of the bending operation wires 13, 13.
Notches 26, 26 are provided in at least two places so as to perform the bending in the direction locally.

Therefore, in normal times, as shown in FIG. 10A, the distal end curved portion 4 of the insertion portion 5 is straight,
Bending operation wire 1 arranged on tip bending portion 4 of insertion portion 5
When one of the three and 13 is heated by energization, the same figure (b)
(C) As shown in FIG.
Notch 2 of polyethylene tube 25 provided on 3 side
The tip bending portion 4 curves from the six portions.

When both of the bending operation wires 13 and 13 disposed on the distal bending portion 4 of the insertion portion 5 are heated by energization,
As shown in FIG. 3D, the distal end bending portion 4 bends in both directions from the cutout portions 26 and 26 of the polyethylene tube 25.

As described above, the distal end bending portion 4 of the portion where the bending operation wires 13 and 13 are disposed is not bent, but a predetermined portion is locally bent, so that a thin lumen, for example, a blood vessel or a bile duct is formed. In the inside, the tip bending portion 4 is bent in a desired direction to improve the insertability or the efficiency of the observation procedure.

FIGS. 11 and 12 show the catheter 1 in which the perforated tube 10 is provided with two channels 27, 27. The channels 27, 27 are provided with a communicating portion 28 which communicates with an adjacent portion. . Therefore, the biopsy forceps 29 can be inserted into one channel 27, and the cooling water can be circulated through the other channel 27 by the syringe 30.

When the bending operation wire 13 made of a shape memory alloy disposed in the perforated tube 10 is electrically heated by the above configuration, the perforated tube 10 is heated and its temperature rises. By flowing water, the porous tube 10 is cooled and overheating can be prevented. In addition, since the two channels 27, 27 are provided with the communicating portion 28 which communicates with the adjacent portions, the flow rate of the cooling water is increased, and the cross-sectional area of the porous tube 10 is reduced. The cooling effect can be enhanced.

The shape of the channel 27 provided in the perforated tube 10 is not limited to FIG. 12, but various shapes such as a three-leaf shape, a daruma shape and a petal shape can be considered as shown in FIG. The area is reduced, and the cooling effect of the porous tube 10 can be enhanced.

As described above, according to the present invention,
A bending operation wire made of a linear shape memory alloy whose length contracts and expands in accordance with a temperature change is disposed on the flexible tube, and a portion of the flexible tube on which the bending operation wire is disposed is provided. The outer diameter should be larger than the bending hardness of the flexible tube.
Partially covered with a tube having
It is characterized in that the degree is higher than other parts .

Therefore, by obtaining a large amount of bending with a short bending portion length, the lumen can be easily inserted into a small and meandering body cavity. As a result, the burden on the operator can be reduced and the patient's burden can be reduced. It has the effect of reducing pain.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a distal end side of a catheter according to a first embodiment of the present invention.

FIG. 2 is a side view showing the distal end side of the catheter of the embodiment.

FIG. 3 is a perspective view showing the entire bending device of the embodiment.

FIG. 4 is a perspective view showing a distal end side of a catheter according to a second embodiment of the present invention.

FIG. 5 is a side view showing the distal end side of the catheter of the embodiment.

FIG. 6 is a perspective view showing a distal end side of a catheter according to a third embodiment of the present invention.

FIG. 7 is a vertical sectional side view of a use state of the embodiment.

FIG. 8 is a perspective view showing a distal end side of a catheter according to a fourth embodiment of the present invention.

FIG. 9 is a perspective view showing a distal end side of a catheter according to a fifth embodiment of the present invention.

FIG. 10 is a side view of the usage state of the embodiment.

FIG. 11 is a perspective view of a catheter having two channels.

FIG. 12 is a sectional view of the catheter.

FIG. 13 is a front view showing different channel shapes of the catheter.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... catheter, 4 ... bending part, 13 ... bending operation wire, 17 ... heat-shrinkable tube.

Claims (1)

(57) [Claims] 1. A bending operation wire made of a linear shape memory alloy whose length contracts and expands in accordance with a temperature change in an axial direction of a flexible tube, and the bending operation wire is provided. Bending the outer diameter of the flexible tube in the portion where
Partially covered with a tube having a hardness higher than the hardness
A flexible tube bending device characterized in that the hardness of the covering portion of the flexible tube is higher than that of the other portion .