JPH066100B2 - Endoscope - Google Patents

Description

Description: TECHNICAL FIELD OF THE INVENTION The present invention relates to an endoscope, and more particularly to an endoscope having an improved bending system for bending a bending portion.

[Technical background of the invention and its problems]

It is known that an endoscope is configured by connecting an operation portion to a rear end portion of an insertion portion formed by sequentially connecting a tip forming portion, a bending portion, and a flexible tube portion.

By the way, in such an endoscope, the bending portion is operated to bend by a hand operation. As such a bending system, conventionally, in addition to inserting the operation wire connected to the distal end portion from the inside of the insertion portion to the inside of the operation portion,
A structure in which the drum connected to the angle knob is rotatably arranged and the end of the previous operation wire is fixed to this drum is used.By rotating the angle knob, the drum is rotated and the bending part is passed through the operation wire. I try to make it bend.

However, in an endoscope that bends using such an angle knob, in addition to using a gear mechanism to reduce torque, it also requires free engagement, which inevitably complicates the bending system, and the operating part. There is a problem that the weight of the

Therefore, in view of this, the one shown in Japanese Utility Model Application No. 59-2344 has been proposed. In this, a shape memory alloy is used for the curved portion, and the curved portion is curved by applying a temperature change to the shape memory alloy.

Although such a curved portion using a shape memory alloy can certainly simplify the configuration of the endoscope by the shape memory effect, on the other hand, the curved portion in contact with the body cavity wall has a shape memory effect. Because it uses an alloy,
The temperature must be elevated to operate the shape memory alloy. Therefore, the wall of the body cavity may be burned, and the temperature of the shape memory alloy cannot be rapidly changed. Therefore, the responsiveness of the curved portion is poor, and there is a demand for a flexible responsive bending operation that can be performed by using a shape memory alloy having the advantage of being able to simplify such a configuration.

[Object of the Invention]

The present invention has been made in view of the above circumstances, and an object thereof is to provide an endoscope capable of performing a bending operation excellent in responsiveness by using a shape memory alloy.

[Outline of Invention]

That is, according to the present invention, one end of the operation wire, which is connected to the connection portion at the bending portion, is inserted into the bending portion, and the operation wire is axially reciprocated so as to pull and loosen the operation wire at the other end of the operation wire at the proximal end side. By connecting a driving unit made of a moving shape memory alloy and providing a means for controlling heating to the shape memory alloy, it is intended to make it possible to perform bending using a rapid temperature change. is there.

Example of Invention

The present invention will be described below with reference to the first embodiment shown in FIGS. 1 to 5. FIG. 1 shows the whole endoscope, 1 is an insertion part formed by sequentially connecting a tip forming part 2, a bending part 3, and a flexible tube part 4 in series, 5 is an operating part, and 6 is a universal cord. is there. Then, the insertion portion 1 and the rear end portion of the universal cord 6 are connected to the operation portion 5, respectively, to form an endoscope body 7. An image guide (not shown) that connects the objective lens (not shown) provided in the tip forming section 2 and the eyepiece 5a provided in the operation section 5 is provided in the insertion section 1, and the tip is also provided. Light guides (not shown) that connect an illumination window (not shown) provided in the component 2 and a connector 6a provided at the tip of the universal cord 6 are respectively inserted, and the front of the tip component 2 from the eyepiece 5a is inserted. You can see it.

On the other hand, 8a and 8b are two operation wires inserted from the inside of the insertion section 1 to the inside of the operation section 5, and 9a and 9b are the operation sections 5.
They are two shape memory elements having the same structure arranged inside. The tip ends of the operation wires 8a, 8a are connected to the tip forming portion 2, and the back end portions thereof are the shape memory element 9 described above.
Operation wires 8a and 8b connected to a and 9b, respectively.
The bending part 3 can be bent using the shape memory effect.

The structure of the shape memory elements 9a and 9b is shown in FIG. Here, the structure of the shape memory elements 9a and 9b will be described. Reference numeral 10 denotes a cylindrical case,
Reference numeral 11 denotes a slidable operating shaft that is provided in the case 10 so as to penetrate therethrough in the axial direction, and 12 is a partition plate that is provided in the middle of the operating shaft 11 so as to partition the inside of the case 10. A reversible coil-shaped shape memory alloy 13 drive unit is installed in the right side space of the case 10 partitioned by the partition plate 12, while a bias spring 14 is installed in the left side space. By applying heat to the alloy 13, the shape memory alloy 13 in which the length required for the bending is stored in advance is operated, and by cooling the alloy, the shape memory alloy 13 is returned to its original state to move the operating shaft 11 back and forth. I am able to The right ends of the respective actuating shafts 11 of the shape memory elements 9a and 9b are connected to the ends of the operation wires 8a and 8b, respectively, to connect the shape memory alloy 13 and the operation wires 8a and 8b. That is, the shape memory alloy 13 is adapted to reciprocate in the axial direction so as to pull and loosen the operation wires 8a and 8b.

On the other hand, in the light source device 15 that sends illumination light to the endoscope through the universal cord 6, the shape memory elements 9a, 9
a heating system 16 for actuating the shape memory alloy 13 of b,
A cooling system 17 is also provided. As the heating system 16, as shown in FIG.
9. The alloy resistance measuring circuit 20 is connected in series, and the alloy resistance measuring circuit 20 and the pulse energization unit 18 are connected together. Then, the output side of the pulse energization unit 18 is
Connected to one end of the shape memory alloy 13 of each shape memory element 9a, 9b through the electric wires 21, 21 inserted in the insertion part 1 so that pulse conduction can be performed to each shape memory alloy 13, 13. There is. Also, alloy resistance measuring circuit 2
The input side of 0 is the wire 2 that is also inserted in the insertion part 1.
2, 22 are connected to the other ends of the shape memory alloys 13 of the shape memory elements 9a, 9b, respectively.
3 resistance can be detected. On the other hand, the control unit 1
Reference numeral 9 is configured so that the number of energizing pulses can be controlled according to various curved displacements, so that an arbitrary operating state can be obtained from a change in heat input to the shape memory alloy 13 and also a shape memory alloy. By grasping the change of the resistance of 13, it is possible to detect how much the shape memory alloy 13 is displaced by comparison and control the number of energizing pulses according to the state. Thereby, the bending angle of the bending portion 3 can be controlled.

On the other hand, the cooling system 17 is configured using an air supply mechanism (not shown) built in the light source device 15. The air supply outlet of this air supply mechanism is communicatively connected to the case 10 of each shape memory element 9a, 9b through the air supply pipe 23 inserted into the insertion portion 1 to supply cooling air into the case 10. As a result, the shape memory alloy 13 displaced by the previous pulse energization can be returned to the original shape. The cooling system 17 is controlled so as to work when the curved portion 3 is returned to the original state. Although not shown, the cooling system 17 and the heating system 16 are operated by the button operation of the operation unit 5, and the cooling system 17 and the heating system 16 constitute the control means 24. .

Then, when the bending portion 3 is bent using the endoscope configured as described above, the operation portion 5 is operated by a button.
As a result, pulse current is applied to the shape memory alloy 13 of the shape memory element 9a on the angled side. The energized shape memory alloy 13 is, as shown in FIG.
It gradually expands against the elastic force of the adjacent bias spring 14, moves the partition plate 12, pulls the operation wire 8a on the angled side toward the hand side, bends the bending portion 3, and bends the tip of the insertion portion 1. The angle will be applied to the section. At this time, the angle is set as shown in FIG. 5 by changing the number of energizing pulses by the control unit 19.
That is, the operating displacement ΔL of the shape memory alloy 13 is in inverse proportion to the resistance of the shape memory alloy 13, and the required bending displacement Δ is used by using the control unit 19 and the alloy resistance measuring circuit 20. Until L is reached, pulsed current with a large number of pulses is applied to increase the heat input to the shape memory alloy 13. Then, the angle of the desired angle is satisfied by comparing the resistance preset in the control unit 19 with the resistance output from the alloy resistance measuring circuit 20, and then the angle is applied to the shape memory alloy 13. Pulse conduction is performed with a small number of pulses so as to compensate for the amount of heat radiated in (3) to maintain the desired angle angle. Note that such an angle angle may be changed by changing the duty ratio instead of changing the number of energizing pulses.

Further, when returning to such a bent state, the shape memory alloy 13 of the shape memory element 9b on the side opposite to the previously operated shape memory element 9a is operated in the same manner as in the case of the previous shape memory element 9a, and at the same time the light source is turned on. By blowing cooling air from the device 15 through the air pipe 23 to the shape memory alloy 13 on the side of the shape memory element 9a, the operated shape memory alloy 13 becomes the fourth.
Return to its original shape as shown and bias spring 14
The operation wire 8a is fed in the direction of loosening by and the curved portion 3 which is curved is returned.

Thus, with the shape memory alloy 13, the operation wires 8a, 8
By operating b, it becomes possible to rapidly change the temperature of the shape memory alloy 13,
The responsiveness of the curved portion 3 can be dramatically improved by using the shape memory alloy 13 having an advantage that the structure can be simplified.

Although the displacement of the shape memory alloy is detected using the alloy resistance measuring circuit in the above-described first embodiment, the invention is not limited to this.
It may be detected by optical means, and a shape memory alloy may be used for the bias spring.
However, when the shape memory alloy is used for the bias spring, the shape memory alloy having the property of shrinking at high temperature is used in the first embodiment.

Further, FIG. 6 shows a second embodiment of the present invention, which uses a gas or fluid as a medium in addition to energization, in contrast to the above-mentioned one in which the shape memory alloy 13 is operated only by energization. The shape of the shape memory alloy 13 is shown to be controllable. Specifically, the shape memory alloy 13 is formed in a rod shape so that one end is fixed and the other end is slidable in the cylindrical case 30 along its axial direction. The shape memory alloy 13 is provided, and the operation wires 8a and 8b are connected by swaging to the other end exposed from the case 20 of the shape memory alloy 13, while the case 30 is provided with the two air supply pipe portions 31 and 31. In addition to energizing, hot water or hot air is circulated from the air supply pipe portion 31 into the case 30 so that the operation wire 8a or the operation wire 8b is slackened and cold water or cold air is circulated. It is obtained so as to pull the wire 8a or the operation wires 8b. Reference numeral 32 represents an electric wire for energizing the shape memory alloy 13.

〔The invention's effect〕

As described above, according to the present invention, on the proximal end side, a drive unit made of a shape memory alloy is connected to the other end of the operation wire so that the shape memory alloy reciprocates in the axial direction. By controlling the heating to the shape memory alloy, it becomes possible to apply a rapid temperature change to the shape memory alloy.

Therefore, it is possible to perform a bending operation with excellent responsiveness by using the shape memory alloy, which has the advantage that the structure can be simplified.

[Brief description of drawings]

1 to 5 show a first embodiment of the present invention,
FIG. 1 is a schematic configuration diagram showing an endoscope in which a shape memory alloy is attached to an operating portion, FIG. 2 is a sectional view showing the structure around the shape memory alloy and the configuration of its control system, and FIG. 3 is at high temperature. 4 is a sectional view showing the state of the shape memory alloy, FIG. 4 is a sectional view showing the state of the shape memory alloy at low temperature, and FIG. 5 is a diagram showing the operating transition of the shape memory alloy from energizing pulses, resistance, etc. FIG. 6 is a sectional view showing the main part of the second embodiment of the present invention. DESCRIPTION OF SYMBOLS 1 ... Insertion part, 3 ... Bending part, 5 ... Operation part, 7 ... Endoscope main body, 8a, 8b ... Operation wire, 13 ... Shape memory alloy drive part, 24 ... Control means.

Claims (1)

[Claims] 1. An insertion portion having a curved portion at its tip, an operation wire inserted through the curved portion and having one end connected to the curved portion, and an operation wire provided at the proximal end side and connected to the other end of the operation wire. An endoscope comprising: a drive unit made of a shape memory alloy that reciprocates in the axial direction so as to pull and loosen the operation wire; and a means for controlling heating to the shape memory alloy.