JP3242434B2 - catheter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a catheter.

[0002]

2. Description of the Related Art Conventionally, as a bending mechanism for a flexible tube such as an endoscope or a catheter, a wire made of a shape memory alloy (hereinafter, referred to as an SMA wire) is looped and arranged in a bending portion, and the SMA wire is electrically heated. By doing so, there is known a device that contracts an SMA wire to bend a curved portion.

[0003]

However, in the conventional bending mechanism for a flexible tube, the heat generated when the SMA wire is energized is transferred from the outside of the bending portion to the living tissue, and the inner wall of the body cavity may be burned. However, there is a problem that it is difficult to ensure safety for a living body.

In order to prevent excessive heating, for example, a cooling method for supplying cooling water into a channel of a catheter is used. In this case, a pump for supplying cooling water or the like must be provided. There is a problem that the structure becomes complicated and the manufacturing cost increases.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a catheter having a simple structure and capable of securing thermal safety to a living body.

[0006]

Means for Solving the Problems and Actions To solve the above-mentioned problems, the invention described in claim 1 is directed to a catheter made of a resin having at least one lumen formed therein, which is inserted into a living body. The catheter body and a predetermined lumen formed in the catheter body are disposed at a portion corresponding to a contact portion between the catheter body and a living body, and bend a distal bending portion of the catheter body by receiving a predetermined traction force. An angle wire to be driven and a shape that is disposed at a portion corresponding to a non-contact portion between the catheter body and a living body in a predetermined lumen formed in the catheter body, and is configured to pull and drive the angle wire by predetermined heat energy. It is characterized by having a driving means made of a memory alloy wire, and an electric heating means for energizing and heating the driving means. Further, according to the invention described in claim 2, via a channel of an endoscope for observing the inside of a living body, at least one or more lumens are formed in a catheter protruding from the channel and inserted into the living body, A resin catheter main body that can be inserted into the channel of the endoscope, and when the catheter main body is protruded from the channel of the endoscope, the catheter main body is disposed in a predetermined lumen corresponding to the protruding portion. An angle wire that receives a predetermined traction force to drive the catheter body to bend, and within the same lumen as the angle wire, when the catheter body is projected from the channel of the endoscope, A shape memory alloy wire disposed in a lumen corresponding to a portion staying at the And having a drive unit consisting of Ya, and electrical heating means for electrically heating said driving means.

[0007]

[0008]

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

FIG. 1 shows a catheter to which a bending mechanism according to a first embodiment of the present invention is applied. The main body of the catheter is formed of a flexible tube 1, and the flexible tube 1 is formed of a multi-lumen tube made of polyurethane.
The flexible tube 1 is provided with a channel 2 through which a small-diameter scope, a guide wire, or the like is inserted, liquid is supplied, or suction is performed. Further, a lumen 3 containing an angle wire 12 and a shape memory alloy wire 10 (hereinafter, referred to as an SMA wire) is formed.

[0010] A curved portion 4 is provided on the distal end side of the flexible tube 1 of the catheter, and a sheath tube 11 is covered on the rear side. A pair of the angle wires 1 are provided in the bending portion 4.
2 is inserted into the lumen 3, and is fixed by the caulking portion 5 at the distal end of the flexible tube 1. The proximal end of the angle wire 12 is connected to the SMA wire 10 whose distal end is bent in a U-shape by the connecting portion 7. The SMA wire 10 is disposed in the non-living body insertion portion 14 that does not contact the inside of the living body cavity. The connecting portion 7 is movably accommodated in a space formed in the driving portion 6.

Angle wire 12 and SMA wire 10
Are generally connected by laser welding.
The tip of the MA wire 10 can be plated and soldered, or can be mechanically connected. Also, SM
The base end of the A-wire 10 is connected to the current-carrying wire 8 by a caulking portion 9, and a current is passed from a current-carrying control device (not shown) connected to the proximal portion of the current-carrying wire 8 to heat and heat the SMA wire. The heat causes the SMA wire to shrink. The SMA wire 10 of the present embodiment is made of a bidirectional shape memory alloy, and is made of a Ti—Ni alloy or Cu—Zn—
Various materials such as Al alloys can be used.
Ni alloys are preferred.

[0012] The power supply control device (not shown) is
The amount of energization is configured to be adjustable, and the energization amount is preferably adjusted by PWM energization.

As shown in FIG. 4, the main body of the catheter is composed of three tubes. First, the living body insertion portion 13 of the catheter is formed of polyurethane, and FIG.
As shown in FIG. 3B, a three-lumen tube, which is a lumen 3a through which the angle wire 12 is inserted and a lumen forming the channel 2, is used. As shown in FIG. 4 (c), the driving section 6 of the catheter has the same catheter outer diameter and channel diameter as the living body insertion section 13, but the shape of the lumen 3b is elliptical and the connecting section The two SMA wires 10 folded back at 7 can be inserted. However, when the SMA wire 10 becomes longer to some extent, the lumen 3
There is a risk of entanglement and short-circuiting in b. Therefore,
In the non-living-body insertion part 14 other than the driving part 6 of the catheter, as shown in FIG. 4D, the SMA wire 10 is inserted into the lumen 3c one by one. In addition, the non-living body insertion portion 14 needs a multi-lumen tube that can withstand the heat of the SMA wire 10 during energization and heating. Therefore, heat-resistant multi-lumen tubes such as Teflon are used.

In order to easily and surely connect the angle wire and the SMA wire, the angle wire 15 is formed in a ring shape as shown in FIG. 15 and SM
The A wires 16 may be crossed and connected. With this configuration, the main body of the catheter is formed of two types of tubes, and the driving section 19 of the catheter has a configuration similar to that of the driving section 6 shown in FIG. Can expand and contract.

The living body inserting section 17 and the non-living body inserting section 18
Has a structure as shown in FIG. The distal end of the angle wire 15 provided on the living body insertion portion 17 is covered and fixed with polyurethane, which is the same material as the catheter main body. Therefore, the SMA wire 16 contracts when the electric heating is performed, the angle wire 15 is pulled, and the distal end of the catheter is To bend. The catheter body can be made of polyethylene, silicon, fluororesin, or the like, in addition to polyurethane.

Next, the operation of the first embodiment will be described.

FIG. 3 shows a state in which the catheter of this embodiment is inserted into a body cavity such as the pancreatic duct 21 through the channel 24 of the endoscope 23 of the side view type.

The SMA wire 10 disposed in the catheter is supplied with a current supply wire 8 by a current supply control device (not shown).
Electricity is supplied via. As a result, the SMA wire 10
The SMA wire 10 is contracted by the heating and the contraction operation of the SMA wire 10 pulls one angle wire 10 to bend the bending portion 4 in a desired direction. The length of the space in the driving portion 6 of the catheter is such that the connecting portion 7 does not contact the end of the space even when the SMA wire 10 is maximally contracted.

The curved portion 4 is more flexible than other portions because the outer tube 11 is not covered. Therefore, the bending due to the contraction of the SMA wire 10 is limited to only the bending portion 4, and the jacket tube 11 does not bend. In addition, the SMA wire 1 which becomes high temperature by energizing heating
0 is located in the channel 24 of the endoscope 23,
Heat transfer to the outside of the jacket tube 11 is kept in the channel 24. Therefore, since only one angle wire 10 is located at the living body insertion portion 13 that is in contact with the living body inner wall and is not heated, the living body inner wall is not adversely affected by heat.

FIG. 5 shows a bending portion of an endoscope to which a bending mechanism according to a second embodiment of the present invention is applied.

The main body of the endoscope insertion portion is formed of a multi-lumen tube, and its curved portion 35 is made of polyurethane, and the rear side from the driving portion needs to have heat resistance to withstand the heating of the SMA wire. It is formed with. Further, the objective lens 30 and the light guide fiber 31
The end portion 32 of the endoscope to which is fixed is formed of a material such as an electrically insulating ceramic or plastic.

A pair of angle wires 26 are inserted into the lumen of the bending portion 35 of the endoscope, and are fixed by the caulking portion 25 at the distal end portion 32 of the endoscope. In addition, the proximal side of the angle wire 26 is connected to a SMA wire 28 having a U-shaped tip at a drive section 27 provided in the endoscope insertion section via a connection section 29.
In addition, the angle wire 26 and the SMA wire 28
The connection is made in the same manner as in the embodiment.

The rear end of the SMA wire 28 is connected to a conducting wire (not shown). In addition, the endoscope tip portion 32
The objective lens 30 disposed in the image guide 33
The image guide 33 extends to a rear eyepiece (not shown). Further, the light guide 31 arranged inside the endoscope insertion portion like the image guide 33 is connected to a light source device (not shown) outside through the insertion portion from the endoscope distal end portion 32.

In this embodiment, when the SMA wire 28 disposed in the endoscope insertion portion is energized by an energization control device (not shown), the SMA wire 10 contracts due to energization heating, and the SMA wire 10 contracts by the contraction operation. Then, the bending wire 35 is bent in a desired direction by pulling the angle wire 26 on one side. In that case, S which becomes high temperature by energization heating
Since the MA wire 28 is located in the lumen of the endoscope insertion portion, the heat of the SMA wire 28 is kept in the lumen. Therefore, since the outer surface of the insertion portion that comes into contact with the inner wall of the living body is not heated, it is possible to prevent the adverse effect of heat on the inner wall of the living body.

The present invention is not limited to the above embodiments, but can be applied to various endoscopes and catheters.

[0026]

As described above, according to the catheter of the present invention, thermal safety for a living body can be ensured with a simple configuration. In particular, since the catheter of the present invention has a main body made of resin and a shape memory alloy disposed in its lumen, it is not necessary to add a configuration for electrical insulation to the shape memory alloy. Therefore, it is possible to eliminate the thermal effect on the living body while ensuring the outer diameter of the insertion portion to be small.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a distal end portion of a catheter according to a first embodiment of the present invention.

FIG. 2 is an explanatory view showing a modified example of a tip portion of the catheter shown in FIG.

FIG. 3 is a perspective view showing a use state of the catheter according to the first embodiment.

4 (a) is an exploded schematic view showing a configuration of a tip portion of the catheter shown in FIG. 1, (b) is a cross-sectional view of a living body insertion portion,
(C) is a cross-sectional view of the drive unit, and (d) is a cross-sectional view of the living body non-insertion unit.

FIG. 5 is a longitudinal sectional view showing a distal end portion of an endoscope according to a second embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Flexible tube, 4 ... Bending part, 10 ... SMA wire (drive member), 12 ... Angle wire, 13 ... Living body insertion part, 14
... non-living body insertion part.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) A61B 1/00-1/32 A61M 25/01

Claims (2)

(57) [Claims] 1. A catheter inserted into a living body, comprising: a catheter body made of resin having at least one lumen formed therein; and a catheter body and a living body at a predetermined lumen formed in the catheter body. An angle wire disposed at a position corresponding to the contact portion and receiving a predetermined traction force to bend the tip bending portion of the catheter main body, and a predetermined lumen formed in the catheter main body, the catheter main body and the living body A drive unit comprising a shape memory alloy wire that is disposed at a position corresponding to the non-contact portion of the above and that pulls and drives the angle wire by predetermined heat energy; and an energization heating unit that energizes and heats the drive unit. A catheter characterized by the above-mentioned. 2. A catheter protruding from a channel of an endoscope for observing the inside of a living body and inserted into the living body, wherein the channel of the endoscope has at least one or more lumens formed therein. A resin catheter main body that can be inserted into the endoscope, and when the catheter main body is protruded from the channel of the endoscope, the catheter main body is disposed in a predetermined lumen corresponding to the protruding portion, and receives a predetermined traction force. An angle wire that drives the catheter body in a curved manner; and a lumen that is in the same lumen as the angle wire, and that corresponds to a portion that remains in the channel when the catheter body is projected from the channel of the endoscope. Driving means comprising a shape memory alloy wire disposed in the inside and for pulling and driving the angle wire by predetermined heat energy And an energization heating means for energizing and heating the driving means.