JPH0371890B2 - - Google Patents

Description

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

Conventionally, as disclosed in (a) 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 attached to a gastrocamera or other imaging device. I made it so that it is installed in succession,
There is a device that bends the flexible portion 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 node rings covered with a water-resistant flexible skin, and has a ridge on the periphery of the end surface of the node ring. and a space between the adjacent nodal rings, and the two attached to the anterior end of the neck as in item (a).
A book string is passed through the raised portion and guided to the operating section, and by pulling any one of the strings, 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) Japanese Patent Application Laid-Open No. 50-141187 discloses that 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. An endoscope designed to allow In this endoscope, if a means for heating the shape memory alloy rod is provided, such as an electric heater, the temperature can be rapidly increased and the shape memory alloy rod can be bent into a desired shape. Even after the power supply is cut off, the temperature of the shape memory alloy rod does not drop rapidly, so it takes a considerable amount of time to return to its original shape, making it difficult to use.

The present invention solves the above-mentioned drawbacks and provides an endoscope that can be deformed and quickly returned to its original state without the need for mechanical operations such as pulling a string. The purpose is to

The endoscope of the present invention includes a shape memory alloy disposed within the insertion section, a means for heating the shape memory alloy, and an elastic body that restores the insertion section to its original shape when not heated. This is a characteristic feature.

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, that is, 40°C, to memorize the shape, and then the pitch of the coil in use is formed at a temperature below the transformation point. When re-formed, this alloy wire retains the elongated coiled state formed above the transformation point.

In the endoscope of the present invention, since the shape memory alloy is configured as a coiled elastic strip 3, the flexible tube 1 always has flexibility and is easy to operate, for example, when inserting or removing the endoscope into a body cavity. It does not put pressure on or damage the wall.

Next, the operation will be explained.

A heater 4 embedded in a rubber-like elastic body 5 fixed at 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. 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 its 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 quickly returns to its original pitch state, and 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, and also to change the degree of bending of the flexible tube 1. By appropriately applying electricity, the flexible tube 1 can be bent in any direction. The rubber-like elastic body 5 and the helical elastic strip 3 may be joined together in various ways other than fixing.

FIG. 5 is an enlarged sectional view showing an embodiment of how to fix the rubber-like elastic body of the flexible tube of the endoscope and the coiled elastic strip according to the present invention. Claw 8 made of shape memory alloy
is formed and stored in the rubber-like elastic body 5 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 gap between both ends of the claw 8 is widened to make it easier to attach the nail 8 at a temperature below the transformation point indicated by the double chain line in the figure. When the temperature is raised, it 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 looseness. 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 modifications can be made within the scope of the claims.

The effects of the present invention are as follows.

(a) Since the flexible tube connected to the tip of the endoscope can be bent without pulling strings such as wires, it is possible to avoid situations in which the string becomes inoperable due to breakage.

(b) After the power supply to the heater is cut off, the flexible tube can quickly return to its original state due to the restoring force of the rubber-like elastic body.

[Brief explanation of drawings]

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 strip elastic body,
6...Lead wire, 7...Photography equipment, 8...Claw.

Claims (1)

[Claims] 1. An endoscope, characterized in that a shape memory alloy is disposed within the insertion section, a means for heating the shape memory alloy is provided, and an elastic body is provided for restoring the insertion section to its original shape when not heated.