JPH07108277B2 - Endoscope - Google Patents

Description

Description: [Industrial application] The present invention relates to an endoscope having a structure in which a bending portion is bent using a shape memory alloy.

[Prior Art] Generally, as a structure for bending a bending portion of an endoscope, an operation wire is inserted into an insertion portion, a distal end of the operation wire is connected to a distal end of the bending portion, and a base end is operated. It is known that the bending portion is connected to an angle knob provided on the, and the angle knob pushes and pulls the operation wire to bend the bending portion.

However, according to such a structure, not only the structure becomes complicated and the diameter of the insertion portion is increased, but also a considerably large operating force is required, which causes poor operability.

Therefore, in order to eliminate such a defect, a structure in which a drive member made of a shape memory alloy is provided in the bending portion and the bending portion is bent by electrically heating the driving member to deform the driving member is put into practical use. Is being done. As such a prior art, there is one disclosed in Japanese Utility Model Laid-Open No. 58-101601.

[Problems to be Solved by the Invention] By the way, in such an endoscope, a plurality of, for example, two driving members are provided in the bending portion, and the bending portion is selectively bent in either the vertical direction. That is done. However, when one of the driving members is electrically heated and deformed to bend the bending portion upward, and then the bending portion is straightened or is bent downward, the one driving member has a temperature equal to or lower than a predetermined temperature. If it does not go down, the drive member becomes a resistance and the bending portion cannot be returned straight or bent downward.

Therefore, if the next bending operation is performed after the temperature of one driving member is lowered, the operation can be performed reliably. However, if the drive member that has been heated once is allowed to cool naturally before the next bending operation is performed, it takes a considerable time until the drive member is cooled, so the bending operation can be performed quickly and quickly. There is a problem of operability that it cannot be performed smoothly. Therefore, it can be considered to supply a cooling fluid to the curved portion to forcibly cool the drive member. However, if the fluid is simply supplied to the bending portion, even the drive member that does not need to be cooled and that is electrically heated to bend the bending portion in the opposite direction is cooled, and the bending portion can be bent quickly. It happens that you can't.

The present invention has been made in view of the above circumstances, and an object thereof is to forcibly cool a drive member that has been deformed by heating and not to cool a drive member that does not need to be cooled. An object of the present invention is to provide an endoscope capable of improving bending operability of a bending portion.

[Means and Actions for Solving Problems] In order to solve the above problems, the present invention comprises an insertion portion having a bending portion at its tip and a shape memory alloy disposed in the bending portion. A drive member, heating means for electrically heating and deforming the drive member to bend the bending portion, and fluid for cooling the driving member, which is provided in the insertion portion, for supplying to the bending portion. And means for controlling the supply means only when the driving member is not electrically heated by the heating means. Then, the drive member that is not electrically heated is cooled by the fluid supplied to the curved portion by the supply means.

[Embodiment] A first embodiment of the present invention will be described below with reference to FIGS. 1 to 3. FIG. 1 shows a waterproof type watertight endoscope 1, which has an operating section 2. The insertion portion 3 and the universal cord 4 are connected to the operation portion 2. The insertion portion 3 is provided with a tip forming portion 7 at the tip of a flexible tube portion 5 via a curved portion 6, and a connector 9 connected to a light source device 8 is provided at the end of the universal cord 4. There is.

A first drive member 11 and a second drive member 12 are arranged on the curved portion 6 so as to be displaced by 180 degrees in the circumferential direction thereof and have a predetermined length along the axial direction. These drive members 11 and 12 are formed in a coil shape from a shape memory alloy such as a Ti-Ni alloy or a Cu-Zn-Al alloy, and their shapes are memorized so that they are deformed in a shrinking direction when heated. . One end of each of the pair of driving members 11 and 12 is connected to the first fixing member 13 fixedly provided on the tip side of the bending portion 6, and the other end is also fixedly provided on the rear end side. It is connected to the second fixing member 14. Therefore, the bending portion 6 is the first
In the drawing, when the first driving member 11 located at the upper side is contracted, it is curved upward, and when the second driving member 12 is contracted, it is curved downward.

The first fixing member 13 is made of an electrically conductive material, and one end of a common lead wire 15 electrically connected to the pair of driving members is connected to the first fixing member 13. That is, one end of the common lead wire 15 is electrically connected to one end of the pair of drive members 11 and 12 via the first fixing member 13. One end of a first lead wire 16 is connected to the other end of the first drive member 11, and one end of a second lead wire 17 is connected to the other end of the second drive member 12. The other ends of the common lead wire 15 and the first and second lead wires 16 and 17 are passed through the universal cord 4 and guided to the connector 9. When the connector 9 is connected to the light source device 8, the other ends of these lead wires are connected to the current-carrying part built in the light source device 8.
It is supposed to be connected to 18.

In addition to the energizing section 18, an energization control section 19 and an air supply pump 21 are provided in the light source device 8. The energization control unit 19 has a first switch provided on the operation unit 2.
22 and the second switch 23 are connected via third and fourth lead wires 24 and 25, respectively. The first switch
When 22 is turned on, the signal is input to the energization unit 18 and the air supply pump 21 via the energization control unit 19. Then, the energizing portion 18 energizes and heats the first driving member 11. Further, when the second switch 23 is turned on and the signal is input to the energization control unit 19, the air supply pump 21 is operated thereby, and at the same time, the energization unit is activated.
The second driving member 12 is electrically heated via 18.

The air supply pump 21 has an air supply tube 26 as an air supply line.
One end of is connected. The air supply tube 26 is passed through the universal cord 4 and the insertion portion 3, and the other end is located inside the bending portion 6. Therefore, the above air supply pump
When 21 is activated, compressed air is blown into the bending portion 6 via the air supply tube 26. The compressed air ejected into the bending portion 6 flows through the insertion portion 3 and the operation portion 2,
The universal cord 4 is discharged to the outside of the endoscope 1 through an opening / closing valve 27 provided on the connector 9 at the end. This on-off valve 27 is a manual type,
It is opened during use and closed during cleaning and disinfection.

The air supply pump 21 is driven by a signal from a drive circuit 28 for a predetermined time as shown in FIG. In other words, the drive circuit 28 is ANDed via the timer 29.
The output side of the circuit 30 is connected, and the first inverting circuit 30a and the second inverting circuit 30b are connected to the input side of the AND circuit 30. A signal when the first switch 22 operates is input to the first inverting circuit 30a, and a signal when the second switch 23 operates is input to the second inverting circuit 30b. It is like this. Therefore, the first,
The air supply pump 21 is driven by the drive circuit 28 for a predetermined time based on the set time of the timer 29 only when the second switches 22 and 23 are not operated.

Next, a case of using the endoscope 1 having the above configuration will be described. When the insertion section 3 is inserted into the body cavity of the subject and the bending section 6 is bent upward, when the first switch 22 is turned on as shown in FIG.
Input is made from 19 to the energization unit 18 and the air supply pump 21. As a result, the first drive member 11 is electrically heated and the air supply pump 21 is operated for a predetermined time. When the first driving member 11 is electrically heated, the first driving member 11 is deformed in the contracting direction, so that the bending portion 6 is bent upward.

Next, when the bending portion 6 is bent downward, the second switch 23 is turned on. Then, the signal is input from the energization control unit 19 to the energization unit 18 and the air supply pump 21. As a result, the air supply pump 21 is operated for a predetermined time, and the second drive member 12 is electrically heated.
Will be curved downwards.

By the way, in such a bending operation, the first drive member
Until the second drive member 12 is energized after the energization of 11 is completed, both the first and second switches 22 and 23 are not operated. Then, the state is input to the drive circuit 28 via the AND circuit 30 and the timer 29, whereby the air supply pump 21 is operated for a predetermined time, and compressed air is ejected to the bending portion 6. As a result, the temperature of the first driving member 11 which has been heated until then decreases in a short time as indicated by T ₁ in FIG. Then, the force for maintaining the memorized shape is removed from the first drive member 11. Therefore, after the air supply pump 21 is stopped, the first drive member 11 is heated when the second drive member 12 is electrically heated to bend the bending portion 6 downward.
Therefore, the bending portion 6 can be smoothly bent downward. After that, when the power supply to the second drive member 12 is turned off, the air supply pump 21 is driven again for a predetermined time in the same manner as described above, whereby the second drive member 12 is driven to the first position. The driving member 11 can be cooled in the same time T ₁ as in the case of forced cooling.

On the other hand, the compressed air ejected from the air supply pump 21 into the bending portion 6 flows to the universal cord 4 through the insertion portion 3 and the operating portion 2, and is opened to the outside from the opening / closing valve 27 provided at the end of the universal cord 4. Will be discharged. Therefore, even if compressed air is jetted into the bending portion 6 to cool the first and second drive members 11 and 12, the internal pressure of the endoscope 1 rises too much due to the compressed air, and the insertion portion 3 The outer skin of universal cord 4 does not burst.

FIG. 4 shows a second embodiment of the present invention. In this embodiment, the on-off valve 27a is replaced by an electrically operated type instead of a manual type, and can be opened by a signal from the energization control section 19. That is, the on-off valve 27a is connected to the first drive member 11
Alternatively, the power supply to the second drive member 12 is turned off, and when the air supply pump 21 is operated for a predetermined time, it is opened at the same time. In this case, the compressed air ejected to cool the first or second drive members 11 and 12 is discharged to the outside by the open / close valve 27a and the bending portion 6 does not need to be bent. Since the opening / closing valve 27a is closed, the liquid can be prevented from entering the inside of the endoscope 1 at the time of cleaning and disinfecting.

5 and 6 show a third embodiment of the present invention, in which the opening / closing valve 27b is opened by mounting the connector 9 on the light source device 8. In other words, the connector 9 has a valve chamber 31
And a through hole 32 for communicating the inside and outside of the connector 9 is formed in the peripheral wall of the valve chamber 31. A valve element 33 is provided in the valve chamber 31.
Is elastically slidable by a coil spring 34 and airtightly held by an O-ring 33a.
The through hole 32 is closed by 3. Further, the light source device 8 to which the connector 9 is connected is provided with a protrusion 35,
When the connector 9 is connected, the projection 35 enters the valve chamber 31 and pushes the valve body 33 against the biasing force of the coil spring 34. Thereby, the inside of the connector 9 communicates with the outside through the through hole 32 and the groove 36 formed in the surface of the light source device 8.

According to such a structure, when the connector 9 is removed from the light source device 8 to wash and disinfect the endoscope 1, for example, the through hole 32 is closed by the valve body 33, and thus the inside of the endoscope 1 is closed. It is possible to prevent the liquid from entering the space.

FIG. 7 shows a fourth embodiment of the present invention. This shows that when a plurality of driving members 41 are electrically insulated from each other in the bending portion 6 and arranged in series, the feeding members arranged in parallel with the driving members 41 are arranged. Spout holes are formed in the air tube 26 at locations corresponding to the respective drive members 41.
42 is formed by drilling. With such a structure, each drive member 41 can be cooled well.

FIG. 8 and FIG. 9 show a fifth embodiment of the present invention, in which the drive circuit 28 for driving the air feeding pump 21 and the AND circuit 30 are connected as shown in FIG. The timer 29 is removed, and as shown in FIG. 8, the air supply pump 21 is always operated when both the first and second switches 22 and 23 are not operated.
I made it work.

FIG. 10 shows a sixth embodiment of the present invention. In this embodiment, a water supply tube 51 is provided in place of the air supply tube 26, and the portion of the water supply tube 51 located inside the curved portion 6 is first and second.
The driving members 11 and 12 are approached. Also, the water supply tube 51
A water supply pump 52 was connected to the water supply pump 52, and the cooling liquid 54 contained in the tank 53 was circulated by the water supply pump 52. Thereby, the first and second driving members 11 and 12 located near the liquid feeding tube 51 are cooled.
That is, the water supply pump 52 is controlled to start and stop in the same manner as the air supply pump 21 of the first and fifth embodiments, and the drive members 11,
The cooling liquid 54 is circulated through the water supply tube 51 only when the 12 is cooled.

FIG. 11 shows a seventh embodiment of the present invention in which the insertion portion 3 is formed of a multi-lumen tube, and the compressed air from the air supply pump 21 is caused to flow through the pipe line 55 formed in the insertion portion 3 and the pipe. The first and second drive members 11 and 12 are provided at a portion of the path 55 located at the distal end of the insertion portion 3, that is, at a portion that becomes the curved portion 6.
Is provided.

FIG. 12 shows an eighth embodiment of the present invention. In this embodiment, a bimorph fan 56 is provided in the bending portion 6 so as to face the first and second driving members 11 and 12. The bimorph fan 56 is composed of a bimorph piezoelectric element 57 and a fixing portion 58 having one end fixed, and when energized by the voltage applying portion 59,
The piezoelectric element 57 swings as shown by a chain line, and the cooling air generated thereby cools the first and second driving members 11 and 12.

The voltage application section 59 is driven by a signal from the energization control section 19. That is, the energization control unit 19 is connected to the first and second switches 22 and 23 for driving the drive members 11 and 12 as in the first embodiment, and these switches 22 and 23 are operated. When it is not turned on, that is, when both the first and second drive members 11 and 12 are not heated by energization, the energization controller 59 energizes the bimorph fan 56. The energizing time to the bimorph fan 56 may be determined by a timer, or may be always driven when the first and second switches 22 and 23 are not operated.

13 and 14 show a ninth embodiment of the present invention, in which the temperature of the driving members 11 and 12 is detected by the thermocouple 61a,
It is measured by the temperature detector 61 only when the driving members 11 and 12 are not energized, and the measurement detection signal is measured by the comparator 62.
To enter. In the comparator 62, the temperature T ₀ detected by the temperature detector 61 is compared with the preset temperature T _1, and a time A when the temperature T ₀ detected by the temperature detector 61 becomes lower than the set temperature T _1. Then, that is input to the drive control unit 63. Thereby, the drive circuit 28 is controlled and the air supply pump 21 is stopped. Also in this embodiment, the first and second drive members are the same as in the above embodiments.
Air pump 21 only when 11 and 12 are not heated electrically
Is activated.

15 to 17 show a tenth embodiment of the present invention. This embodiment is almost the same as the ninth embodiment except that the drive member is
Instead of measuring the temperature of 11 and 12, the resistance value is detected by the resistance value detection unit.
The difference is that the detection is performed at 65. The detected resistance value R detected by the resistance value detection section 65 is compared with the set resistance value R ₁ by the comparator 62, and when the detected resistance value R detected by the detection section 65 is smaller than the set resistance value R _1. That is, when the temperature of the first or second drive member 11, 12 is higher than the predetermined temperature, the air supply pump 21 causes the drive control unit 28 and the drive circuit 28 to operate.
It is designed to be driven through. It should be noted that, as shown in FIG. 16, in the air supply pump 21, not only the signal from the comparator 62 but also the signals from both the first and second switches 22 and 23 are not operating. When it is input from the AND circuit 30 to another AND circuit 66, it is driven by the signal from this AND circuit 66. Further, in this embodiment, the driving members 11 and 12 are energized by the energizing portion 18 in pulses.

The present invention is not limited to the above embodiments, and the on-off valve may be provided at a place other than the connector, for example. Further, for example, four driving members may be provided at intervals of 90 degrees in the circumferential direction, and the bending portion may be bent not only in the vertical direction but also in the horizontal direction. The arrangement state and the number thereof are not limited at all. Not. Further, when a plurality of driving members are provided, a plurality of air supply tubes may be provided.
Furthermore, if the supplied fluid is cooled in advance, the cooling time of the drive member can be shortened.

〔The invention's effect〕

As described above, according to the present invention, in the case of the endoscope having the structure in which the bending portion is bent by the driving member made of the shape memory alloy, the fluid for cooling the driving member is supplied to the bending portion by the supplying means. The supplying means is operated only when the driving member is not electrically heated. Therefore, it is possible to cool the drive member having the bending portion bent in the predetermined direction in a short time, so that the operation of returning the bending portion to the original position or bending the bending member in a direction other than the predetermined direction can be performed quickly and surely. It is possible to improve the sex. Further, since the drive member is not forcibly cooled while being electrically heated, the heated drive member is not cooled to decrease the response of the bending operation.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of an endoscope showing a first embodiment of the present invention, FIG. 2 is an operation explanatory diagram thereof, FIG. 3 is a control circuit diagram of an air supply pump thereof, and FIG. FIG. 5 is a schematic diagram of a connector portion showing a second embodiment of the invention, FIG. 5 is a configuration diagram of an opening / closing valve showing a third embodiment of the present invention, and FIG. 6 is a configuration diagram showing a state in which the opening / closing valve is also opened, FIG. 7 is a configuration diagram of a drive member and an air supply tube showing a fourth embodiment of the present invention, FIG. 8 is an operation explanatory view showing a fifth embodiment of the present invention, and FIG. 9 is the same air supply. FIG. 10 is a control circuit diagram of a pump, FIG. 10 is a schematic view of fluid supply means showing a sixth embodiment of the present invention, and FIG. 11 is a schematic view of fluid supply means showing a seventh embodiment of the present invention.
FIG. 12 is a schematic diagram of a fluid supply means showing an eighth embodiment of the present invention, FIG. 13 is a control circuit diagram of an air feeding pump showing a ninth embodiment of the present invention, and FIG. 14 is the same operation. Explanatory drawing, fifteenth
FIG. 16 is a control circuit diagram of an air supply pump showing a tenth embodiment of the present invention, FIG. 16 is a control circuit diagram of the same air supply pump, and FIG. 17 is an operation explanatory view thereof. 3 ... insertion part, 6 ... curved part, 8 ... tip part, 11,
12 ... First and second drive members, 18 ... Energizing section, 19 ... Energization control section, 21 ... Air supply pump (supply means), 22, 23 ...
First and second switches, 26 ... Air supply tube (supply means).

Claims (1)

[Claims] 1. An insertion portion having a curved portion at its tip, a drive member made of a shape memory alloy disposed in the curved portion, and the drive member is electrically heated and deformed to thereby deform the curved portion. A heating means for bending the member, a supply means provided in the insertion portion for supplying a fluid for cooling the driving member to the bending portion, and the above-mentioned only when the driving member is not electrically heated by the heating means. An endoscope comprising: a control unit that operates a supply unit.