JPH11337844A - Endoscope - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an endoscope permitting user to change a direction of observation from the front of the insertion part to the side. SOLUTION: In the endoscope 1 which has an image guide 3 for transmitting image information in a main body 2 and a reflecting means installed in the neighborhood of the tip part of the main body 2, the reflecting means is provided with a cantilever 5 formed into a flat plate from a shape-memory alloy and a reflecting surface 6, and as a heating means for heating the cantilever 5, the shape-memory alloy is self-heated via lead wires 7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an endoscope for obtaining image information of a body cavity or the like.

[0002]

2. Description of the Related Art Conventionally, various endoscopes have been developed for the purpose of observing and diagnosing the inside of a body cavity and the like. Among them, for example, JP-A-6-165750 "Endoscope utilizing photothermal conversion"
And JP-A-5-88093 "Fiberscope", JP-A-5-3
No. 1066 “Tubular insertion tool” discloses an endoscope that can change the observation direction using a shape memory alloy, that is, can swing.

[0003] These devices are capable of observing a wide range by bending an optical fiber bundle for guiding image information, for example, by the deformation force of a shape memory alloy and changing the direction of the tip. The use of these devices makes it possible to control the direction of the tip of the optical fiber bundle, and has a feature that a target site can be easily observed.

[0004]

In these conventional devices, the optical fiber bundle itself serving as an image guide is curved in order to change the observation direction.
However, the optical fiber bundle cannot be bent smaller than the minimum radius of curvature, and the angle of curvature is greatly restricted in a body space, particularly in a narrow space such as a blood vessel.
It is difficult to use such that it is directed sideways in the insertion axis direction.

[0005] In the present invention, the observation direction can be switched between the front and side of the insertion section, and the inner wall of the luminal tissue around the insertion section can be observed even in a narrow space such as a luminal organ or a vessel. An object of the present invention is to provide an endoscope that realizes a highly reliable endoscope with a light burden on a patient by realizing the endoscope with a simple and small mechanism.

[0006]

This and other objects are attained by the following inventions (1) to (5).

(1) In an endoscope having a long insertion portion, image guide means for transmitting image information into the insertion portion, and reflection means provided near the tip of the insertion portion, the reflection means Further comprises a heating means for heating the cantilever, comprising a cantilever made of a shape memory alloy formed in a plate shape and a reflecting surface, wherein the heating means generates self-heating by energizing the shape memory alloy. An endoscope characterized by the following.

(2) The endoscope according to (1), wherein the cantilever is an omnidirectional shape memory alloy.

(3) The endoscope according to (1), wherein the cantilever is a bidirectional shape memory alloy.

(4) The above-mentioned (1), wherein the cantilever is a one-way shape memory alloy, and the laser beam reflecting means further includes a bias spring material for applying a force to bend the cantilever. The endoscope as described.

(5) The endoscope according to the above (1), further comprising cooling means for supplying and discharging a cooling fluid around the cantilever.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an endoscope according to the present invention will be described.
This will be described in detail with reference to preferred embodiments shown in the accompanying drawings.

FIGS. 1 and 2 are views for explaining the configuration of the distal end portion of the endoscope according to the present invention. FIG. 1 shows a state of observing the side, and FIG. This shows a state in which is observed. FIG. 3 is a front view of the state of FIG. 2 and a sectional view taken along line AA, and FIG. 4 is a front view of the state of FIG. 1 and a sectional view taken along line BB of FIG.

1 to 4, an endoscope 1 is provided with an image guide 3 made of an optical fiber bundle inside a tubular main body 2 which is an insertion portion into a body cavity.
A tip cap 4 made of a light-transmitting material such as acrylic resin or quartz is attached to the tip of the main body 2 so that visible light can be transmitted. A CCD camera (not shown) is connected to the base end of the endoscope 1, and the image information transmitted by the image guide 3 is converted into an electric signal and displayed on a TV monitor or the like.

The cantilever 5 is an actuator made of an omnidirectional shape memory alloy, and a reflective surface 6 is provided on the surface of the cantilever 5 so that visible light can be efficiently reflected. As a heating means, a lead wire 7 for energization is used.
Is provided so as to be connected to the cantilever 5.
By applying a current to the cantilever 5 via the lead wire 7, the shape memory alloy itself generates heat, and the amount of heat necessary for deformation is obtained.

At the entrance end of the image guide 3, a lens 9 for forming an image is provided. The diameter of the incident end of the image guide 3 with the lens 9 attached is 1.5 mm, and the size of the reflecting surface 6 provided on the cantilever 5 is 1 m.
m × 1 mm, which are contained in a tubular main body 2 having an outer diameter (diameter) of 3 mm.

The main body 2 is formed so as to have a gap around the image guide 3, and the surrounding gap can function as an air supply lumen 10a and an exhaust lumen 10b. A partition wall 11 is formed in the inner hole of the main body 2. The partition wall 11 separates the air supply lumen 10 a and the exhaust lumen 10 b while fixing the image guide 3. Through these lumens 10a and 10b, carbon dioxide gas is circulated as a cooling fluid from a cooling fluid circulation device (not shown) from the base end of the image guide 2. The carbon dioxide gas used to cool the device
It only flows through the inside of the main body 2 and does not leak out of the main body 2.

FIGS. 2 and 3 show a state in which the cantilever 5 is not energized by the lead wire 7 (a state in which there is no heating).
As shown in FIG. The reflecting surface 6 is completely out of the field of view of the image guide 3, and in this state, the field of view of the endoscope is directed toward the axial end of the main body 2 (forward).

When a current is applied to the lead wire 7 to cause the shape memory alloy to self-heat and gradually increase the temperature, the cantilever 5 is moved to the image guide 3 as shown in FIGS.
It crosses the line of sight at approximately 45 degrees. In this embodiment, the temperature at this time is about 80 degrees, but since the heating is very local near the cantilever 5, the outside of the main body 2 is not heated. At this time, a state in which the entrance end of the image guide 3 is viewed from the front end direction of the main body 2 is illustrated. As shown in FIG. Becomes
The line of sight of the image guide 3 is reflected by the reflecting surface 6, so that a state 90 ° lateral from the axis of the main body 2 can be observed.

In this embodiment, since the omnidirectional shape memory alloy is used as the shape memory alloy, the cantilever 5 can take an arbitrary angle between the state shown in FIG. 1 and the state shown in FIG. Can be done. At this time, depending on the angle of the cantilever 5, an arbitrary direction between the front side and the side in the axial direction of the main body 2 is captured in the field of view.

When the power supply to the heater 8 is stopped and the heating is stopped, the shape memory alloy is removed from the lumens 10a and 10b in the main body 2.
It is rapidly cooled by the flow of carbon dioxide gas ventilated through it, with the result that the shape memory alloy returns to its normal shape (straight state). Since the temperature of the cantilever 5 can be rapidly lowered by this ventilation cooling, the cantilever 5 can be quickly returned to the normal temperature angle as compared with the time of natural cooling, and the speed of changing the observation angle can be improved. I can do it.

The line of sight of the image guide 3 can be scanned by intermittently repeating energization of the heater 8. Also, if you want to fix the irradiation in a certain direction,
The amount of current may be adjusted so that the temperature of the shape memory alloy is constant.

Here, when observing the light reflected by the reflecting surface 6, the observation image is a mirror image as compared with when observing the front of the main body 2 directly. Therefore, when displaying the image information converted into an electric signal on a TV monitor or the like, it is preferable to display the image information with the left and right reversed. In the present embodiment, the energization of the heater 8 and the image reversing process are linked to eliminate an uncomfortable feeling when switching images.

In this embodiment, an omnidirectional shape memory alloy is used as the shape memory alloy, but a bidirectional shape memory alloy may be used. Two-way shape memory alloys have two specific angles which can be held by the cantilever (usually 45 degrees with respect to the straight line and the line of sight of the image guide).
Degrees) and cannot hold any angle between them, but otherwise can be used in a similar fashion.

Further, a one-way shape memory alloy may be used as the shape memory alloy, and a bias spring material for applying a force to bend the bias memory material may be laminated on the cantilever, and a combined structure may be used. With this configuration, the angle of the cantilever obtained by bending the cantilever by the bias spring and the angle of the cantilever stored in the shape memory material when heated by the heating unit are obtained.
Since two angles are obtained, the angle of the visual field changes according to the degree of heating, and two directions can be observed.

The shape memory alloy used for the cantilever 5 is preferably a NiTi alloy, a Cu-Zn-Al alloy, a Cu-Al-Ni alloy, or the like. The transformation point of these shape memory alloys is preferably about 40 to 80 degrees. The transformation temperature should be selected so that heat does not leak out of the catheter 2 and there is no risk of deformation during non-heating.

The reflecting surface 6 can be obtained by forming a metal thin film on the surface of the cantilever 5 via an electric insulating film. Specifically, Al, Ti, Pt, A
By depositing a metal such as u, a reflective surface having a high reflectance can be suitably obtained. In addition, the surface of the shape memory alloy itself can be used as a reflection surface by subjecting the surface of the shape memory alloy to mirror finishing.

The embodiments of the present invention described above are described to facilitate understanding of the present invention, and the present invention is not limited to the embodiments. Therefore, each element disclosed in the above embodiments includes all design changes and equivalents belonging to the technical scope of the present invention.

For example, although this embodiment has been described as a medical endoscope, the present invention may be applied to use in an industrial field such as an internal inspection of a machine.

[0030]

As described above, according to the present invention, since the scanning of the observation field of view of the image guide is realized by the change in the angle of the cantilever driven by the shape memory alloy, the main body does not move and the wide range is obtained. Observation becomes possible. That is, it is possible to scan the field of view of the endoscope even in a narrow space such as a lumen organ, and it is possible to perform observation and diagnosis efficiently and safely.

Further, since the self-heating of the shape memory alloy is used for heating the shape memory alloy, there is no need to separately provide a heater for heat generation, and there is no internal loss that may cause the heater to bend or deform. Driving force can be obtained efficiently. Further, since the mechanism for moving the field of view is very simple and small, the diameter of the endoscope itself can be reduced, and the physical burden on the patient to be diagnosed can be reduced.

[Brief description of the drawings]

FIG. 1 is a perspective view of a distal end portion showing an embodiment of an endoscope of the present invention.

FIG. 2 is a perspective view of a distal end portion showing an embodiment of the endoscope of the present invention.

FIG. 3 is a front view and a side sectional view of the state of FIG. 2;

FIG. 4 is a front view and a side sectional view of the state of FIG. 1;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Endoscope 2 Main body 3 Image guide 4 Tip cap 5 Cantilever 6 Reflective surface 7 Lead wire 8 Lens

Claims (5)

[Claims] 1. An endoscope comprising: a long insertion portion; image guide means for transmitting image information into the insertion portion; and reflection means provided near a distal end of the insertion portion. It has a cantilever made of a shape memory alloy formed in a flat plate shape and a reflecting surface, and further has a heating means for heating the cantilever, wherein the heating means is a means for generating self-heating by energizing the shape memory alloy. An endoscope, which is characterized in that there is. 2. The endoscope according to claim 1, wherein said cantilever is made of an omnidirectional shape memory alloy. 3. The endoscope according to claim 1, wherein the cantilever is made of a bidirectional shape memory alloy. 4. The apparatus according to claim 1, wherein the cantilever is made of a one-way shape memory alloy, and the laser beam reflecting means further includes a bias spring material for applying a force to bend the cantilever. Endoscope. 5. The endoscope according to claim 1, further comprising cooling means for supplying and discharging a cooling fluid around the cantilever.