JPH1024014A - Actuator and swinging endoscope using the reof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable an endoscope end to be swung through high angles although of a short size by providing, in a spiral groove in a main body tube, a competitive type expanding part, secured to the main body tube at the front and rear of the spiral groove and in which a pair of shape memory material parts are laid, and a towing wire coupled to at least one of the shape memory material parts. SOLUTION: A competitive type expanding part 2 comprising a pair ofcoil parts 23, 24 welded together at a connection 25 is laid along a spiral grove 11 in a main body tube 1 and is welded to the main body tube 1 at both ends 21, 22. A towing wire 3 is provided while its end 31 is welded to the portion of the coil part 23 near the connection 25, and the towing wire 3 is spirally passed through the coil of the coil part 2 from the end 31, is drawn out, and secured to the end of an endoscope. The coil parts 23, 24 are made of shape memory materials with different shape memory temperatures, which are made to retain shapes that are contradictory as to expansion and contraction, so that expansion and contraction of the coil parts 23, 24 can vary the swinging angle of the endoscope end via the towing wire.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an actuator having an antagonistic expansion / contraction portion composed of a pair of shape memory members, and a swing endoscope using the same.

[0002]

2. Description of the Related Art In recent years, the inside of the human body and various devices,
There is a demand for an endoscope that allows observation at a wide angle as much as possible. In that case, it is necessary to freely swing the tip of the endoscope having a mirror at the tip. As its swing mechanism, the conventional method of directly connecting the distal end of the endoscope and the operation unit at hand with a pulling wire and adjusting the degree of pulling of the pulling wire to determine the swing angle, from a pair of shape memory material parts Various methods have been put into practical use or proposed, such as a recent method using an actuator having an antagonistic telescopic portion. In the above-mentioned actuator, which has been recently proposed, a coil of a shape memory material is disposed along the longitudinal direction of the endoscope, one end of which is provided at the distal end of the endoscope, and the other end of which is provided at an appropriate position following the endoscope. And the end of the endoscope is swung by expansion and contraction based on the shape memory of the coil. The antagonistic expansion and contraction section has a pair of shape memory material sections made of a shape memory material having different shape memory temperatures, and the pair of shape memory material sections also store mutually opposite shapes in terms of expansion and contraction. That is, when one shape memory material portion is heated to its own shape memory temperature, the shape memory material portion returns to its own memory shape from the deformed state imparted when the shape of the other shape memory material portion returns, and at that time, Is deformed. On the other hand, the other shape memory material part applies a deformation to one shape memory material part when returning to its own memory shape from the deformation state given at the time of the shape recovery of the one shape memory material part.

In the recently proposed actuator, the angle at which the distal end of the endoscope can swing is determined by the amount of expansion and contraction of the shape memory material coil. A shape memory coil is required. However, in such a case, a long shape memory coil is installed at the distal end portion of the endoscope, which causes a problem that the originally required sufficient flexibility of the distal end portion is impaired.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide an actuator which is short and can swing the endoscope tip at a high angle.

[0005]

The endoscope according to the present invention has the following features. 1. A main body tube having a spiral groove on the surface, an antagonistic expansion / contraction portion comprising a pair of shape memory material portions laid in the spiral groove of the main body tube and fixed to the main body tube at both front and rear sides of the spiral groove, and the main body tube And a traction wire laid in the spiral groove and connected to at least one of the shape memory members of the antagonistic expansion and contraction portion. 2. 2. The actuator according to the above item 1, wherein the antagonistic expansion / contraction part is a coil of a shape memory wire. 3. 3. The actuator according to the above item 2, wherein the pulling wire laid in the spiral groove passes through the coil of the shape memory wire. 4. The actuator according to any one of the above items 1 to 3, wherein the two pulling wires are connected to another shape memory material part. 5. 5. An endoscope in which the endoscope is inserted into the main body tube of the actuator according to any one of the above items 1 to 4, and the other end of the pulling wire is fixed to the end of the endoscope. mirror.

[0006]

In the actuator according to the present invention, since the antagonistic expansion / contraction part composed of the pair of shape memory members is laid in the spiral groove of the main body tube, it has a spiral shape. Therefore, when the endoscope is inserted into the main body tube, the expansion and contraction portion exists in a spiral state on the endoscope, and the amount of expansion and contraction in the helical direction of the traction wire in the longitudinal direction of the endoscope. It will be reflected in the amount of traction. Therefore, by increasing the number of spiral windings of the spiral groove of the main body tube, the towing length in the longitudinal direction of the endoscope can be increased.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
FIG. 1 is a perspective view of an embodiment of the actuator of the present invention. FIG. 2 is a perspective view of another embodiment of the actuator of the present invention. FIG. 3 is a perspective view of still another embodiment of the actuator of the present invention. 1 to 3, the same parts are indicated by the same numerical values.

In FIG. 1, reference numeral 1 denotes a main body tube, 11 denotes a spiral groove formed on the surface of the main body tube 1, 2 denotes a coil-shaped antagonistic expansion / contraction portion formed of a pair of shape memory members, and 3 denotes a pulling wire. . The antagonistic telescopic portion 2 is laid in the main pipe along the spiral groove 11 and both ends 21 and 22 are fixed to the main pipe 1 by welding. The antagonistic expansion / contraction part 2 includes a pair of coils of a coil part 23 and a coil part 24, and both parts are welded at a connection part 25 located substantially at the center of the antagonistic expansion / contraction part 2. The pulling wire 3 is fixed by welding to the coil portion 23 at a position where the distal end 31 is close to the connection portion 25, passes spirally through the coil of the coil portion 23 from the distal end 31, and is further provided on the main body tube 1. It extends under the arch-shaped guide 12 provided in front of the main body tube 1.

The coil portion 23 and the coil portion 24 are made of a shape memory material having different shape memory temperatures, and have shapes that are mutually inconsistent with respect to expansion and contraction. That is, the shape of the coil portion 23 is contracted when the coil portion 24 returns from the deformed state (extended state) imparted when the coil portion 24 returns to its own memory shape to loosen the pulling force of the pulling wire 3. And the coil portion 24
Has the effect of retracting the coil portion 23 from its deformed state (extended state) when returning to its own memory shape from its deformed state (extended state), and pulling the pulling wire 3 while deforming the coil section 23. Eggplant Coil part 23 and coil part 24
The above-mentioned expansion and contraction can be achieved, for example, by alternately applying power to both ends of each coil portion as terminals and heating with generated Joule heat.

The material of the main body tube 1 is preferably stainless steel, copper, other metals, heat-resistant plastics such as polypropylene, poly-4-methylpentene-1, nylon, polyester, polyvinyl chloride, polyurethane, and polysulfone. There, the groove on the surface is laser processing,
It can be formed by electric discharge machining, excimer laser machining, or the like. In the case where the coil portions 23 and 24 are heated by energization, after forming the grooves, the entire surface where the coil portions 23 and 24 come into contact by applying and baking an electrically insulating varnish such as polyimide, polyamideimide, or formal. Need to be electrically insulated.

The width of the spiral groove 11, the width of the spiral bank 14 between the adjacent spiral grooves, the number of spiral turns of the coil portions 23 and 24, the spiral inclination angle, and the like are determined by the size and application of the actuator of the present invention. For example, when the main pipe 1 has an outer diameter of about 0.5 to 2 mm and a length of about 30 to 50 mm, the width of the spiral groove 11 is 0.1 to 1 mm, and the width of the spiral ridge 14 is 0. .05 to 0.3 mm, coil part 23,
The number of spiral windings of 24 is preferably 10 to 100 times, and the spiral inclination angle is preferably about 20 to 70 degrees with respect to the longitudinal axis of the main tube 1.

When the actuator according to the embodiment of FIG. 1 is mounted on an endoscope and the other end of the pulling wire 3 is fixed to the end of the endoscope, the above-described expansion and contraction of the coil portions 23 and 24 is performed. By adjusting the pulling force of the pulling wire 3 by means of, the swing angle in one direction of the distal end of the endoscope can be freely changed.

A specific example of the embodiment shown in FIG. 1 will be described below.
Laser processing stainless steel tube with an inner diameter of 0.8 mm, wall thickness of 0.4 mm and length of 30 mm, and approximately 0.5 mm in width, 0.3 mm in depth, 70 degree spiral inclination angle, total spiral winding in the approximate center in the longitudinal direction Twenty-seven times, a spiral groove having a spiral embankment width of 0.1 mm is formed, and then substantially the entire surface of the stainless steel tube including the spiral groove portion is coated with a polyimide electric insulating varnish by electrodeposition coating and baked to obtain an average film thickness. A main body tube 1 was obtained by forming a polyimide insulating layer having a thickness of 30 μm. The length of the spiral groove in the longitudinal direction of the main body tube 1 is 20 mm. Ti- with 150 μm outer diameter
A shape memory coil obtained by winding a Ni alloy shape memory wire around a coil outer diameter of 0.45 mm is referred to as a coil portion 23, while
A shape memory coil obtained by winding a shape memory wire made of a Ti—Ni alloy having an outer diameter of 150 μm to a coil outer diameter of 0.45 mm was used as a coil portion 24, and both ends were welded to each other to obtain an antagonistic expansion / contraction portion 2. Further, the pulling wire 3 was inserted into the coil portion 23, and the tip was welded to a position of the coil portion 23 at a distance of about 5 mm from the welding point. The thus obtained antagonistic telescopic portion 2 was wound into the spiral groove of the main body tube 1 together with the pulling wire 3, and both ends were welded to the main body tube 1, respectively. The actuator prepared through the above steps was mounted on the end of an endoscope having an outer diameter of 0.75 mm, and the other end of the pulling wire 3 was fixed to the end of the endoscope to operate the actuator. However, it was possible to swing up to 60 degrees at a current of 100 mA. Incidentally, in order to operate the same degree of swing with a conventional actuator having a linearly arranged shape memory coil, a long shape memory coil as long as 100 mm is required.

The embodiment of FIG. 2 has exactly the same structure as the embodiment of FIG. 1 except that a pulling wire 4 is added in addition to the pulling wire 3 and that the additional improvements are added. The pulling wire 4 is fixed by welding to the coil portion 24 at a position where the tip 41 is close to the connection portion 25, and the subsequent portion is provided on the main pipe 1 by spirally passing through the coil portion 24. It extends around the cylindrical small projection 26, then extends under the arch-shaped guide 13 provided on the opposite side of the guide 12 to the front of the main body tube 1.

The embodiment of FIG. 2 differs from the embodiment of FIG.
The tip of the endoscope can be swung right and left in both directions. The working principle will be described. First, in the embodiment of FIG. 2, the extension end of the pulling wire 3 is fixed to the end of the endoscope by attaching to the endoscope. The other end of the pulling wire 4 is fixed to another position of the mirror tip.
In this state, when the coil portion 23 is extended and the coil portion 24 is contracted, the pull wire 3 is pulled, and the pull wire 4 is pulled.
Relaxes and loses traction. Therefore, the distal end of the endoscope swings in the direction in which the pulling wire 3 is pulled. Conversely, when the coil portion 24 is extended and the coil portion 23 is contracted, the pull wire 4 is pulled, and the pull wire 3 relaxes. Therefore, the tip of the endoscope swings in the direction in which the pulling wire 4 is pulled, that is, in the direction opposite to the above.

In the present invention, bidirectional swinging in the left and right directions can be carried out by cascading the two embodiments shown in FIG. 1 to the distal end of the endoscope in addition to the embodiment shown in FIG. In that case, one of the above-mentioned two is placed with the endoscope in one direction,
The other one is mounted and operated so that the endoscope is swung in the other direction.

The endoscope can be swung in four directions by using four embodiments of FIG. 1 or two embodiments of FIG. When four embodiments of FIG. 1 are used, two of them are swung bilaterally on a plane in two directions, and the remaining two are swung in a bidirectional manner on a plane orthogonal to the plane. I will make you shake. The embodiment of FIG.
In the case of using one of them, one of them swings on a certain plane in both left and right directions, and the other one swings on a plane orthogonal to the plane in both directions of left and right.

The actuator of the present invention can be operated by other means in addition to the method of directly energizing and heating the coil portions 23 and 24 described above.
For example, various heating elements may be provided near the coil portions 23 and 24. FIG. 3 shows an embodiment of the present invention equipped with an optical fiber as a heating means. In the embodiment of FIG. 3, a large number of lateral grooves 16 are formed at appropriate intervals over the entire surface of the main tube 1 on the side of the coil portion 24, and the heating optical fiber 5 is disposed in each groove 16. The structure is exactly the same as that of the embodiment of FIG. 1 except that a number of cutouts 15 are provided in the spiral bank 14 of the main pipe 1. The notches 15 are provided in a row so that light emitted from each optical fiber 5 can irradiate the coil portions 24 and 23 as shown. Although the width of the notch 15 and the number of optical fibers 5 to be installed are different depending on the size of the actuator of the present invention, particularly the coil portions 23 and 24, the width of the notch 15 is generally 50.
About 500 μm, and the number of optical fibers 5 to be installed is 3 to 3
About 0 is appropriate. By adjusting the amount of irradiation energy from the optical fiber 5, the coil portion 24 can be heated to a desired temperature and required operations can be performed.

The actuator prepared in the above paragraph 13 is modified as shown in FIG. 3, in which ten optical fibers 5 are arranged at equal intervals on the surface of the main body tube 1 and the width 2
Each notch 15 of 00 μm was provided. When the laser beams were radiated from the optical fiber 5 and the coil portions 23 and 24 were selectively heated, the head could be swung at a maximum swivel angle of 60 degrees with a laser output of 100 mW.

[0020]

According to the actuator of the present invention, since the antagonistic expansion and contraction portion composed of a pair of shape memory material portions is spirally wound around the main body tube, as a result, a sufficient traction length can be obtained even if the entire actuator length is short. Have. Therefore, the short actuator of the present invention can finely swing an endoscope, a catheter, and the like.

[Brief description of the drawings]

FIG. 1 is a perspective view of an embodiment of an actuator according to the present invention.

FIG. 2 is a perspective view of another embodiment of the actuator of the present invention.

FIG. 3 is a perspective view of still another embodiment of the actuator of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Main body pipe 11 Spiral groove 2 Antagonistic expansion-contraction part 3 Pulling wire

Claims (5)

[Claims] 1. An antagonistic expansion / contraction part comprising a main body tube having a spiral groove on its surface, and a pair of shape memory material parts laid in the spiral groove of the main body tube and fixed to the main body tube on both front and rear sides of the spiral groove. And a pulling wire laid in the spiral groove of the main body tube and connected to at least one shape memory material portion of the antagonistic expansion / contraction portion. 2. The actuator according to claim 1, wherein the antagonistic telescopic part is a coil of a shape memory wire. 3. The actuator according to claim 2, wherein the pulling wire laid in the spiral groove passes through the coil of the shape memory wire. 4. The actuator according to claim 1, wherein the two pulling wires are connected to different shape memory portions. 5. The endoscope is inserted into the main body tube of the actuator according to claim 1, and the other end of the pulling wire is fixed to the end of the endoscope. Swing endoscope.