JPH0248249B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is used to deeply explore the inner walls of relatively narrow tortuous passages in living bodies such as the stomach and intestines, and other objects that cannot be detected from the outside for various purposes. This relates to the improvement of endoscopes for

As a conventional example, (a) as disclosed in Japanese Patent Publication No. 38-22693, an elastic strip is wound into a spiral shape, its outer periphery is covered with a flexible multi-layered covering, and the tip is equipped with a gastrocamera or other imaging device. Some devices have devices connected in series, and the flexible portion can be bent by pulling any one of two strings whose tips are attached to two points at the front end of the neck.

(b) The device disclosed in Japanese Utility Model Publication No. 41-5593 has a continuous arrangement of rubber-like elastic joint rings covered with a water-resistant flexible skin, and has a raised ridge on the periphery of the end face of the joint ring. At the same time, a space is provided between adjacent joint rings, and as in item (a), the two strings attached to the front end of the neck are passed through the protrusion and guided to the operating section, and any one of the strings is inserted. When pulled, the neck is tilted laterally.

(c) What is disclosed in Japanese Utility Model Publication No. 41-6621 is a flexible tube having a similar structure using a guide ring instead of the elastic node ring described in item (b).

In all of these endoscopes, the flexible portion is bent by pulling the string. If the string is pulled too strongly, it will break and become inoperable.

(d) JP-A-50-141187 discloses a method in which a rod made of a shape memory alloy is arranged along the wall of the insertion portion, and the rod is bent by heating it to a temperature higher than its transformation point, thereby bending the insertion portion. A catheter is described that allows the In such catheters, the shape memory alloy rod only bends in one direction, so the insertion section also bends in only one direction.
It has the disadvantage of poor operability.

The present invention solves the above-mentioned drawbacks and allows for deformation without mechanical operations such as pulling a string, while ensuring sufficient space for the arrangement of the image guide, light guide, and various tubes. It is an object of the present invention to provide a safe endoscope that can be bent in any direction without loss of flexibility.

The endoscope of the present invention includes a coiled shape memory alloy disposed within the insertion portion, and a plurality of heating means for heating the coiled shape memory alloy.
The present invention is characterized in that the coiled shape memory alloy is changed in the axial direction by heating by the heating means, thereby bending the insertion portion.

The present invention will be described in detail below with reference to the drawings.

FIG. 1 is a longitudinal cross-sectional view of a flexible tube that constitutes an insertion section of an embodiment of an endoscope of the present invention. The outer periphery of the flexible tube 1 is covered with a flexible multi-layered covering 2. A coiled elastic strip 3 made of a shape memory alloy is disposed within the flexible portion of the flexible tube 1, and heaters 4 are placed on the sides at four opposing positions as shown in FIG. The embedded rubber-like elastic body 5 is fixed. Power is supplied to the heater 4 via a lead wire 6.

FIG. 2 is a cross-sectional view of one embodiment of the flexible tube of the endoscope of the present invention shown in FIG. Inside the coiled elastic strip 3, a light guide, a fiber bundle constituting an image guide, tubes constituting various channels, lead wires for power supply, and the like are housed. Note that four rubber-like elastic bodies 5 containing heaters 4 are disposed in two directions that are mutually opposed and perpendicular to each other.

FIG. 3 is an enlarged perspective view of the heater portion in one embodiment of the flexible tube of the endoscope of the present invention shown in FIG. 1. The structure is such that a heater 4 such as a nichrome wire is bent and buried in a heat-resistant rubber-like elastic body 5 such as silicone rubber.

FIG. 4 shows an optical system for forming an image at the tip of the flexible tube of the endoscope of the present invention or a photographing device 7 such as a gastrocamera.
FIG. In the figure, a gastrocamera is shown as an example of the imaging device 7. The above-mentioned endoscope neck refers to the curved flexible part shown in the figure.

As the shape memory alloy, for example, a wire of an alloy of titanium and nickel having a transformation point of 40° C. is used. This alloy wire is formed into a coil that is more elongated than the pitch of the coil actually used at a temperature above the transformation point, i.e., 40℃, to memorize the shape, and then formed into a coil in the used condition at a temperature below the transformation point. When re-formed, this alloy wire retains the elongated coiled state formed above the transformation point.

Next, the operation will be explained.

A heater 4 embedded in a rubber-like elastic body 5 fixed to four opposing positions on the sides of the coiled elastic strip 3.
When power is supplied to any one of the above, the heater 4 passes through the rubber-like elastic body 5 and heats the portion of the helical elastic strip 3 adjacent to the rubber-like elastic body 5 to a temperature higher than the transformation point, and the helical elastic The strip 3 changes to the longer pitch state that the alloy wire had memorized. Since the other parts of the coiled elastic strip 3 remain in a steady state, as a result, the flexible tube 1 bends so that the part heated by the heater 4 is on the outside, as shown in FIG. At this time, the rubber-like elastic body 5 on the outside of the curved portion is stretched. When the power to the heater 4 is turned off, the temperature of the alloy wire falls below the transformation point, and due to the elastic restoring force of the stretched rubber-like elastic body 5, the coiled elastic strip 3 returns to its original curve. The flexible tube 1 returns to its straight state. Therefore, it is possible to change the degree of bending of the flexible tube 1 depending on the degree of the current supplied to the heater 4, and it is also possible to change the degree of bending of the flexible tube 1.
By appropriately energizing the individual heaters 4, the flexible tube 1 can be bent in any direction. Furthermore, since the four heaters 4 are arranged inside the flexible tube 1, it is safe because the body wall will not be burned. Note that the rubber-like elastic body 5 and the coiled elastic strip 3
There are various ways of fixing other than fixation.

FIG. 5 is an enlarged sectional view showing an embodiment of the method of fixing the rubber-like elastic body of the flexible tube of the present invention to the helical elastic strip. A claw 8 made of a shape memory alloy is formed at a temperature above the transformation point temperature of the alloy so that both ends of the claw 8 are closed at an acute angle than the U-shape as shown by the solid line in the figure. The coiled elastic strip 3 is embedded in a rubber-like elastic body 5 and formed with a wide spacing between both ends of the claw 8 so that it can be conveniently attached at a temperature below the transformation point temperature shown by the double chain line in the figure. When the temperature is raised above the transformation point, the coiled elastic strip 3 returns to the memorized shape, that is, the original solid line shape, and the coiled elastic strip 3 can be held in place without any "backlash". can. In the figure, double-headed arrows indicate the direction of expansion and contraction of the rubber-like elastic body 5.

Note that the present invention is not limited to the above embodiments, and various changes can be made within the scope of the claims.

The effects of the present invention are as follows.

(b) Since the insertion section connected to the tip of an endoscope can be bent without pulling a string such as a wire, it is possible to avoid a situation where the string becomes inoperable due to breakage.

(b) By providing a plurality of heating means and selectively supplying power to them, it can be bent in any direction, improving operability.

(c) Since the plurality of heating means are arranged within the insertion section, it is safe and does not cause burns to the body wall.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view of one embodiment of the flexible tube of the endoscope of the present invention, FIG. 2 is a cross-sectional view of the above-mentioned embodiment, and FIG.
The figure is an enlarged perspective view of the heater section in the above embodiment.
The figure is a front view of the above embodiment in which a photographing device for image formation is connected to the tip of the flexible tube, and FIG. It is an enlarged sectional view of one example of the method of fixing with a shaped elastic strip. DESCRIPTION OF SYMBOLS 1...Flexible tube, 2...Multiple covering, 3...Tilted elastic strip, 4...Heater, 5...Rubber-like elastic body,
6...Lead wire, 7...Photography equipment, 8...Claw.

Claims (1)

[Claims] 1 A coiled shape memory alloy is disposed within the insertion portion, and a plurality of heating means are provided for heating the coiled shape memory alloy, and the coiled shape memory alloy is heated by the heating means. 1. An endoscope characterized in that the insertion portion is curved by changing the insertion portion in the axial direction.