JPH05163A - Medical tube - Google Patents

Abstract

PURPOSE:To provide a medical tube which ensures a desired amount of bending. CONSTITUTION:A member 3 comprising a shape memory alloy having a shape of bending stored is arranged for a bending part 9 and the member 3 is heated to be deformed in shape so that the bending part 9 is bent. In a medical tube 1 thus arranged. the member 3 is provided for the bending part 9 in plurality and arranged to be separated from one another in the axial direction of the bending part while being made free to slide axially.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a medical tube such as an endoscope or a catheter, which is provided with a member made of a shape memory alloy in which a bent shape is memorized, and which bends.

[0002]

2. Description of the Related Art Conventionally, medical tubes such as catheters and endoscopes have been constructed by, for example, a member made of a shape-memory alloy having a linear shape or a plate shape in the lumen of a multi-lumen tube as an insertion portion (hereinafter, simply SMA member Is provided and the SMA member is heated by a heating means such as electric heating to be deformed into a bent shape, thereby performing a bending operation.

[0003]

By the way, the SMA
When the member deformed into a bent shape, the SMA member could not slide in the axial direction of the tube within the lumen in which it was inserted, which prevented the SMA member from deforming into a bent shape. Therefore, there is a possibility that a desired bending amount may not be obtained or the bending may not occur because the bending amount is small. The present invention has been made in view of the above circumstances, and an object thereof is to provide a medical tube capable of obtaining a desired bending amount.

[0004]

In order to achieve the above object, the present invention provides a member made of a shape memory alloy in which a bent shape is stored in a curved portion, and the member made of the shape memory alloy is heated. In the medical tube for deforming the shape by bending to bend the bending portion, in the bending portion,
A plurality of members made of the shape memory alloy were separately arranged in the axial direction of the bending portion, and the members were slidably arranged in the axial direction.

[0005]

With the above structure, each member made of the shape memory alloy is deformed into a bent shape while sliding in the axial direction of the bending portion. Further, the force that hinders the deformation of the member into the bent shape due to the sliding is reduced as much as possible, so that the shape deformation of the member is efficiently performed.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a first embodiment of the present invention. As shown in FIG. 1 (a), for example, a catheter 1 as a medical tube is formed of a flexible multi-lumen tube 2. This multi-lumen tube 2
Normally, various materials such as silicone resin, polyurethane, polyethylene, and Teflon are formed, but a material that can withstand a temperature rise of the SMA member 3 described later may be appropriately selected. The tube 2 also has two lumens 4, 5. Of these, the first lumen 4 is opened at the distal end of the catheter 1 and is used as a channel for performing liquid feeding, suction or the like by an operation from the proximal side. The second lumen 5 is located, for example, in the vicinity of the outer peripheral portion of the tube 2, and its tip is closed by a sealing member 6 made of a resin of the same material as the tube 2. Further, a plurality of plate-shaped SMA members 3 ... Are arranged in the second lumen 5 so as to be separated from each other in the axial direction of the catheter 1. Also, the most distal SMA member 3
The other SMA members 3 except the above can be slid in the axial direction of the catheter 1 in the second lumen 5 by utilizing the spaces 7 on the front and rear sides. The portion where these SMA members 3 are arranged is the curved portion 9 of the catheter 1.

These SMA members 3 are made of various shape memory alloy materials such as Ti-Ni alloys, Cu-Zn-Al alloys, and Fe alloys.
System alloys are preferred. Further, the SMA members 3 ... Are unidirectional ones that are deformed into a memorized shape by being heated, and the memorized shape has a bent shape bent in an arc shape as shown in FIG. 1 (c). Then, the transformation temperature is set to the body temperature or higher. In this case, the temperature is preferably about 50 ° C. or lower, but about 1 ° C. by combining various cooling and heat insulating means.
It can be set up to about 00 ° C.

The adjacent SMA members 3 are electrically connected to each other by connecting the adjacent SMA members 3 in series by a lead wire 8a. In addition, the rear end of the SMA member 3 located closest to the hand side is connected to the end of the lead wire 8 that is inserted into the second lumen 5 and that is connected to an unillustrated energization control device at the hand side. ing. On the other hand, the SMA member 3 located closest to the tip side
Is fixed to the sealing member 6, and the vicinity of its tip is connected to the lead wire 8. Then, the lead wire 8 is inserted into the second lumen 5 while passing the side of the SMA member 3 and is connected to the power supply control device (not shown) on the hand side. That is, in the second lumen 5, the SMA members 3 ... Are in an electrically conductive state and, except for the SMA member 3 at the tip, are in a non-fixed and slidable state.

Further, the energization control device is the catheter 1
The amount of current supplied to the SMA members 3 can be controlled according to the bending amount of the bending portion 9. In this case, energization for heating the SMA members 3 ...
M (pulse width modulation) energization is preferred. At this time, it is desirable to control the heating of the SMA members 3 by controlling the duty ratio to control the bending amount. At this time, when the voltage application pause time (duty interval), S
It is also possible to detect the change in resistance value of the MA members 3 ... And perform feedback control for controlling the duty so as to obtain a constant resistance value. Next, the operation when the bending portion 9 of the catheter 1 having the above-described configuration is bent will be described.

First, at room temperature or body temperature, as shown in FIG. 1 (a), each SMA member 3 is urged and deformed by the elasticity of the multi-lumen tube 2 to become a straight shape of its initial molded shape. ing.

When the bending portion 9 is bent,
A voltage is applied to the SMA members 3 by PWM energization, for example, to heat the SMA members 3 ...
As a result, the unfixed SMA members 3 are restored to the stored bending shape while sliding in the second lumen 5 in the axial direction of the catheter 1 by utilizing the spaces 7 on the front and rear sides, respectively, and bend. The part 9 is curved in the bending direction. Of course, the most advanced SMA member 3 is the sealing member 6
Although sliding is slightly suppressed by the other SMA members 3, ...
Similarly to the above, the rear space 7 is used for sliding to restore the bent shape.

Further, if the temperature of the SMA member 3 is lowered below the transformation temperature by stopping the energization of the SMA member 3, the restoring force of the multi-lumen tube to the molded shape becomes the bent shape of the SMA member 3. By overcoming the restoring force to be deformed, the catheter 1 elastically returns to its original straight shape.

Therefore, the catheter 1 as the medical tube having the above-mentioned configuration has the SMA member 3 in front of and behind the SMA member 3 which is arranged apart from each other in the axial direction of the bending portion 9.
Has a slidable space 7, which allows the SM
Since the force that hinders the deformation of the A members 3 ... to the bent shape is reduced as much as possible, the shape deformation of the SMA members 3 ... Is efficiently performed. Therefore, a desired amount of bending can be obtained, and the amount of bending can be improved as compared with the related art.

Although the catheter 1 of this embodiment is unidirectionally curved by the unidirectional SMA members 3, ..., It may be unidirectionally curved by the bidirectional SMA members 3. That is, for example, the SMA member 3 ...
In addition, the linear shape is memorized on the low temperature phase side at room temperature or body temperature, and the arcuate bent shape is memorized on the high temperature phase side as shown in FIG. 1 (c) to give a bidirectional function. It is a swing curve.
This improves the resilience response of the catheter 1 to the straight shape after the power supply is stopped.

Further, the lead wire 8 connected near the tip of the most advanced SMA member passes through the side of the SMA member to form an S wire.
Instead of inserting the lumen in the same lumen as the MA member, another lumen may be newly provided in the tube 2 and inserted there, thereby improving the slidability of the SMA member 3.

Further, the degree of bending of each SMA member 3 may be different. That is, for example, the radius of curvature of the SMA member 3 arranged closer to the distal end side may be reduced so that the SMA member 3 can be bent smaller. As a result, it is possible to improve the insertability and observability into the living body duct.

FIG. 2 shows a second embodiment of the present invention. Note that, in the following, in each embodiment, portions common to FIG. 1 are denoted by the same reference numerals in the drawings, and description thereof will be omitted.

As shown in FIG. 2, a catheter 15 as a medical tube of this embodiment has three lumens 4,
Flexible multi-lumen tube 16 having 5,17
Is formed by. Among these, the inside of the first lumen 4 and the second lumen 5 has the same configuration as that of the first embodiment. The third lumen 17 is provided at a position symmetrical to the second lumen 5 with respect to the axis of the catheter 15, and the elastic wire 18 is inserted therein. Also,
The tip of the third lumen 17 is closed by a sealing member 6 made of resin of the same material as the tube 16. The elastic wire 18 is made of a piano wire, a stainless steel thin wire for spring, a superelastic alloy wire, or the like which is processed into a linear shape as shown in the drawing, and its tip is fixed to the sealing member 6. The rest of the configuration is the same as in the first embodiment.

Therefore, the catheter 15 as the medical tube having the above-mentioned structure has the same function and effect as those of the first embodiment, and after the energization of the SMA members 3 ... Arranged in the second lumen 5 is stopped. The curved portion 19 returns to the linear shape by the elastic force of the elastic wire 18 in addition to the elastic force of the multi-lumen tube 16. In the case of the above configuration, the bending force is larger than that in the first embodiment, but there is an advantage that the responsiveness until returning to the linear shape after the energization is stopped is improved.

FIG. 3 shows a third embodiment of the present invention. As shown in FIG. 3, a catheter 25 as a medical tube according to the present embodiment has a lubricating layer 26 formed on the outer periphery of an SMA member 3 ... Arranged in the second lumen 5, and other configurations. Are the same as those in the first embodiment (some are not shown). The lubricating layer 26 may be coated with Teflon, or may be coated with a solid lubricant such as molybdenum disulfide.

Therefore, the catheter 25 having the above structure
Has the same effect as the first embodiment,
Due to the lubricating layer 26, the SMA member 3 is different from that of the first embodiment.
The slidability of ... Can be improved and the amount of bending can be increased.
Even if the structure of this embodiment is applied to the second embodiment, the same effect can be obtained.

FIG. 4 shows a fourth embodiment of the present invention. As shown in FIG. 4, each SMA member 3 ... Arranged in the second lumen 5 of the catheter 30 as the medical tube of the present embodiment has a plurality of concave portions along the entire outer circumference or both upper and lower surface portions. A (thin portion) 31 is provided.
The other configuration is the same as that of the first embodiment (not shown in part). Further, the SMA member 3 of the second embodiment can be similarly provided with the recessed portion (thin portion) 31.

Therefore, the catheter 30 having the above structure
Has the same effect as the first embodiment,
The recesses 31 reduce the frictional force between the SMA members 3 ... And the inner surface of the second lumen 5, enhance the slidability of the SMA members 3 ... And increase the amount of bending as compared with the first embodiment. You can Even if the structure of this embodiment is applied to the second embodiment, the same effect can be obtained.

FIG. 5 shows a fifth embodiment of the present invention. As shown in FIG. 5, an endoscope 35 as a medical tube according to the present embodiment has an insertion portion 3 that is inserted into a body cavity or the like.
6 is formed of a flexible multi-lumen tube 38. The base end of the insertion section 36 is connected to an operation section (not shown). The tube 38 is made of the same material as that of each of the above-mentioned embodiments, and has three lumens 39, 40, 41. Of these, an image guide fiber bundle 42 as a bundle of a plurality of image guide fibers 42, a light guide fiber bundle 43 as a bundle of a plurality of light guide fibers, an objective lens 44, etc. are observed in the first lumen 39. The optics are tightly integrated. Of these observation optical systems, a plurality of objective lenses 44 ... Are fitted in a cylindrical lens frame 45.
Then, in the rear end portion of the lens frame 45, the front end portion of the image guide fiber bundle 42 is located at the most proximal end side of the objective lens 4.
It is fitted until it comes into contact with 4, and is fixed, for example.
Further, a plurality of light guide fibers 43 are concentrically arranged on the outer periphery of the image guide fiber bundle 42 including the lens frame 45, and the light guide fiber 4 is provided.
The front end of 3 and the front end of the lens frame 45 are located on substantially the same plane as the front end of the insertion portion 36. That is, the plurality of light guide fibers 43 are tightly inserted into the first lumen 39 by tying them together with the lens frame 45 and the image guide fiber bundle 42, and are fixed, for example, by adhesion.
Further, the proximal end side of the light guide fiber 43 has an insertion portion 36
It is guided through the inside to the operation section side and connected to a light source device (not shown). The image guide fiber 42 is also guided through the insertion portion 36 into the operation portion and is connected to an eyepiece portion provided in the operation portion. Therefore, the light from the light source device (not shown) is emitted from the light guide fiber 43.
The light emitted from the tip of the insertion portion 36 via the light is irradiated to the irradiation target, and the reflected light from the irradiation target passes through the objective lenses 44 ... And forms an image on the front end surface of the image guide fiber 42. , Is transmitted to the eyepiece by the image guide fiber 42 and can be observed through the eyepiece.

On the other hand, the second lumen 40 is located, for example, in the vicinity of the outer peripheral portion of the tube 38, and the tip thereof is closed by the sealing member 6 formed of resin of the same material as the tube 38. Also, the third lumen 41 is
It is provided at a position symmetrical to the second lumen 40 with respect to the axis of the insertion portion 36, and its tip is closed by a sealing member 6 made of resin of the same material as the tube 36. Then, in the second lumen 40 and the third lumen 41, a plate-shaped first SMA member 46 and a second SMA member 47, which are made of the same material as each of the above embodiments, are arranged, The portion where the SMA members 46 and 47 are arranged is the bending portion 37 of the endoscope insertion portion 36. Further, the tip ends of the SMA members 46 and 47 are fixed to the sealing member 6, respectively. Furthermore, each SM
Near the centers of the A members 46 and 47, thin-diameter portions 46b and 47b, which are thinned by electrolytic polishing, are provided. That is, in other words, in the first SMA member 46, two SMA members (large diameter portions) 46 are provided in the same lumen.
a and 46a are arranged separately from each other in the axial direction of the insertion portion 36, and two SMA members (large diameter portions) 46a and 4a are provided.
6a is connected to each other by a member of the same quality (small diameter portion 46b). When the insertion portion 36 of the endoscope 35 has a straight shape, the small diameter portion 4
6b and 47b are in a loosened state as shown. In addition, the SMA member (large diameter portions 46a, 47a) on the rear side of the small diameter portions 46b, 47b uses the space 48 formed by the small diameter portions 46b, 47b to insert the lumens 40, 41 into the insertion portion 36. It can slide in the axial direction.

By the way, the second lumen 40 and the third lumen 40
The SMA members 46 and 47 arranged in the lumen 41 are stored so as to be curved outward of the insertion portion 36. That is, the endoscope 3 is viewed from the direction shown in FIG.
As seen from FIG. 5, the SMA member 46 in the second lumen 40 is curved so as to bow upward, and the SMA member 47 in the third lumen 41 is remembered so as to bow downward.

The rear ends of the SMA members 46 and 47 are inserted into the lumens 40 and 41 that are the same as the SMA members 46 and 47, respectively, and are connected to the above-described energization control device (not shown) on the hand side. The ends of the connected lead wires 8 are connected. On the other hand, each SMA member 46,
The lead wire 8 is connected to the tip of 47. The lead wire 8 is inserted into the lumens 40 and 41 that are the same as the SMA members 46 and 47, and is connected to the power supply control device on the hand side. Next, the endoscope 35 having the above configuration
The operation when the bending portion 37 is bent will be described.

For example, when the bending portion 37 is bent in the direction in which the third lumen 41 is located, the third lumen 4
A voltage is applied to the second SMA member 47 in 1 by, for example, PWM energization to heat the second SMA member 47 to the transformation temperature or higher. As a result, as shown in FIG. 5C, in the second SMA member 47, the large-diameter portions 47a of the second SMA member 47 come closer to each other, and the small-diameter portion 47b of the second SMA member 47 slides in the third lumen 41 while further loosening. The bow shape, which is a memorized shape, is restored, and the bending portion 37 is bent in the direction in which the third lumen 41 is located. At this time, the third lumen 41
The first SM in the second lumen 40 located opposite to
On the contrary, the A member 46 slides while the large diameter portions 46a thereof move away from each other and the loosened small diameter portion 46b extends.

On the contrary, when the bending portion 37 is bent in the direction in which the second lumen 40 is located, the power supply to the second SMA member 47 in the third lumen 41 is stopped,
The first SMA member 46 in the second lumen 40 may be energized to heat the first SMA member 46 to the transformation temperature or higher. By the reverse operation described above, the bending portion 37 bends in the direction in which the second lumen 40 is located.

Instead of forming the small diameter portions 46b and 47b, the SMA thin wire may be fixed to the front and rear large diameter portions 46a and 47a by welding. Further, it is more effective to apply the third embodiment to this embodiment.

Therefore, the endoscope 35 as the medical tube having the above-described structure has the same effect as that of the first embodiment, and is provided in the lumens 40 and 41 which are symmetrical with respect to the axis of the insertion portion 36, respectively. S curved in opposite directions
By arranging the MA members 46 and 47, the bending portion 37
Is advantageous because it can be curved in both of these directions.

FIG. 6 shows a sixth embodiment of the present invention. Catheter 5 as the medical tube of the present embodiment
5 is composed of a tube 56 having a superposed structure, which is composed of an inner tube 57 and an outer tube 58 arranged concentrically outside the inner tube 57. Then, for example, the tip of the tube 56 is closed by a sealing member (not shown), and in the space 59 between the inner tube 57 and the outer tube 58, a plurality of SMA members 3 ...
The lead wires 8 and 8a (not shown) are arranged by the same means as in the first embodiment. Further, the plurality of SMA members 3 ... And the lead wires 8, 8a (partially shown in the drawing) are also provided in the space 59 where these SMA members 3 ... No.) is arranged by the same means as in the first embodiment. Further, the SMA members 3 ... Are stored so as to curve toward the outer side of the catheter 55 as in the previous embodiment. Note that the SMA members 3, ... May be arranged not by the above means but by other means in each of the above-described embodiments.

Therefore, the catheter 55 as the medical tube having the above-mentioned structure is similar to the fifth embodiment in that the SMA is used.
The bending portion 57 can be bent in both directions in which the members 3 are arranged, and the tube 56 and the catheter 55 can be simplified.

By the way, various treatment tools including the above-mentioned medical tube are conventionally known, but the treatment tool shown in FIG. 7 is used, for example, to collect a foreign substance swallowed by mistake in the body. It is the grasping forceps 65. The conventional grasping forceps has a plurality of claws 66 ...
It is inserted through the channel 68 of No. 7 and guided to the target site in the body. Then, in collecting the foreign matter 69, first, the foreign matter 69 is brought close to the open state of the claw 66, and the foreign matter 69 is positioned in the space surrounded by the plurality of claws 66. After that, the claw 66 is closed by pulling the claw 66 into the endoscope 67, and thereby the foreign matter 69 is gripped and collected. However, if the foreign matter 69 is gripped by such an operation, when the nail 66 is pulled into the endoscope 67 and the nail 66 is closed, the nail 66 may be pulled from the foreign matter 69 and the foreign matter 69 may not be grasped well. The gripping forceps 65 shown in FIG. 7 can sufficiently solve these problems.
That is, the grasping forceps 65 shown in FIG. 7 has the three claws 66 fixed to the fixing portion 70, and the wire insertion hole 72 through which the wire 71 is inserted is provided near the tip of each claw 66. The wire 71 is the wire insertion hole 7 of each claw 66.
2 is passed through and one end is fixed to one claw 66. Further, the other end of the wire 71 is inserted through the grasping forceps 65 and is connected to, for example, a wire operating means (not shown). Therefore, for example, when the wire 71 is pulled by the wire operating means, the claw 66 is closed as shown in FIG. 8 and the foreign matter 69 is reliably gripped. Further, when the wire 71 is loosened, the claw 66 can return to the original open shape by its elastic force. Therefore, since the foreign matter 69 can be grasped without pulling the claw 66 into the endoscope 67, the claw 66 is not pulled from the foreign matter 69, and reliable foreign matter recovery can be realized. Further, when the foreign matter 69 is positioned in the space surrounded by the three claws 66, the wire 71 may hinder the work thereof. Therefore, as with the grasping forceps 75 shown in FIG.
The wire insertion hole 72 may be provided on the proximal end side of the claw 76. This facilitates the work of positioning the foreign matter 69 in the space. In addition, as shown in FIG. 10, the wire insertion hole 7 is fixed without fixing one end of the wire 71 to the claw 76.
Alternatively, it may be inserted through the gripping forceps 75 like the other end through the wire 2 and connected to the wire operating means. As a result, even if the nail 76 is damaged as shown in FIG.
Since it becomes a lifeline, the claw 76 does not have to fall off from the grasping forceps 75. Note that the method of gripping a foreign object by operating the wire in this way can also be applied to gripping forceps 80 as shown in FIG. That is, one end of the wire 71 is fixed to the wire fixing portion 82 provided inside the grasping forceps 80, the wire 71 is passed through the wire insertion hole 83 of the grasping portion 81, and the other end is inserted into the grasping forceps 80. For example, it is connected to the wire operating means. Of course, such a technique can be applied to many other treatment tools.

[0035]

As described above, according to the present invention,
Since the shape of the SMA member is efficiently deformed, a desired amount of bending can be obtained, and the amount of bending can be improved as compared with the related art.

[Brief description of drawings]

FIG. 1 (a) is a longitudinal sectional view of a catheter as a medical tube showing a first embodiment of the present invention, and FIG. 1 (b) is (a).
2 is a vertical cross-sectional view taken along the line AA, and (c) is a vertical cross-sectional view showing a curved state of the catheter of (a).

FIG. 2 (a) is a longitudinal sectional view of a catheter as a medical tube showing a second embodiment of the present invention, and FIG. 2 (b) is (a).
FIG. 6 is a vertical sectional view taken along line BB of FIG.

FIG. 3 is a schematic partial sectional view showing the vicinity of a lumen in which an SMA member of a catheter as a medical tube showing a third embodiment of the present invention is arranged.

FIG. 4 is a schematic sectional partial view showing the vicinity of a lumen in which an SMA member of a catheter as a medical tube according to a fourth embodiment of the present invention is arranged.

5A is a vertical cross-sectional view of an endoscope as a medical tube showing a fifth embodiment of the present invention, and FIG. 5B is a C of FIG.
-C is a vertical cross-sectional view taken along the line C, and (c) is a vertical cross-sectional view showing a curved state of the endoscope of (a).

FIG. 6 is a cross-sectional view of a catheter serving as a medical tube according to a sixth embodiment of the present invention as seen from the axial direction.

FIG. 7 is a partial cross-sectional view showing a claw-type grasping forceps in an open state and an endoscope into which the claw-type grasping forceps is inserted.

8 is a partial cross-sectional view showing a closed state of the claw-type grasping forceps of FIG. 7.

9 is a partial cross-sectional view showing a modified example of the claw-type grasping forceps of FIG. 7.

FIG. 10 is a partial cross-sectional view showing another modified example of the claw-type grasping forceps of FIG. 7.

11 is a partial cross-sectional view showing a state when the claw-type grasping forceps of FIG. 10 is broken.

FIG. 12 is a partial cross-sectional view showing another example of the grasping forceps.

[Explanation of symbols]

 1, 15, 25, 30, 55 ... Catheter 3, 46, 47 ... SMA member 9, 19, 37, 57 ... Bending portion 35 ... Endoscope

Claims (1)

Claim: What is claimed is: 1. A member made of a shape memory alloy, which stores a bending shape, is disposed in a bending portion, and the member made of the shape memory alloy is heated to deform its shape to cause the bending. In a medical tube for bending a portion, in the bending portion,
A medical tube characterized in that a plurality of members made of the shape memory alloy are arranged apart from each other in the axial direction of the bending portion, and the members are slidably arranged in the axial direction.