JPH0795996B2 - Endoscope - Google Patents

Description

TECHNICAL FIELD The present invention relates to an endoscope in which a bending drive unit is provided in an insertion portion.

[Prior Art] In recent years, by inserting a slender insertion portion into a body cavity, various treatments can be performed by observing organs in the body cavity or the like and using a treatment instrument inserted in a treatment instrument channel as necessary. Endoscopes are widely used.

By the way, there is an endoscope in which an insertion portion is provided with a bendable portion on the distal end side so that the bendable portion can be operated to bend. As means for operating the bending portion, there is a means for providing a bending operation knob on the operation portion and rotating the bending operation knob, and a means for providing a driving means such as a motor near the bending portion.

For example, Japanese Unexamined Patent Publication No. 61-106126 discloses a small-sized endoscope having a simplified structure in which a vibration wave motor is provided as a driving means in the vicinity of a curved portion of an insertion portion. in this way,
Providing the driving means in the vicinity of the bending portion has advantages that the response of the bending operation is improved, the inspection can be performed with a minimum of operations, and the pain of the patient can be reduced.

On the other hand, since the bending portion is bent frequently in use, the built-in object is more likely to be damaged than the other portions of the insertion portion. Therefore, in the curved portion, the built-in object is covered with a protective tube to prevent damage.

[Problems to be Solved by the Invention] By the way, the length of the protective tube of the built-in object provided in the bending portion is such that the end surface of the protective tube is closer to the operating portion side than the connecting piece of the rearmost joint piece even when bending. It is set.

Further, the internal components of the insertion portion are packed as much as possible so that the outer diameter of the insertion portion is made as thin as possible in order to reduce the pain of the patient.

In addition, the driving portion of the vibration wave motor has a larger outer diameter than the driving force transmitting portion and requires a larger space.

Therefore, like the part covered with the protective tube,
When the drive section is arranged at a position where the internal area of the insertion section is the largest, the outer diameter of the insertion section must be increased by the difference between the cross-sectional areas of the drive section and the driving force transmission section. It will increase the patient's pain.

[Object of the Invention] The present invention has been made in view of the above circumstances, and it is possible to prevent the outer diameter of the insertion portion of the insertion portion from increasing even if the bending driving means is provided in the insertion portion. The purpose is to provide an endoscope.

[Means and Actions for Solving Problems] The endoscope according to the present invention is provided with an insertion portion connected to an operation portion,
A bendable bending portion is provided, a bending driving means for bending the bending portion is provided inside the insertion portion, and an outside portion is provided inside the insertion portion so that the operation portion side has a small diameter near the bending portion. In a housing in which a built-in object having a changed diameter is housed, the bending drive means is arranged closer to the operating portion than a position where the outer diameter of the built-in object changes.

In the present invention, since the large-diameter portion of the built-in article and the bending driving means do not overlap each other in an arbitrary cross section in the axial direction of the insertion section, the maximum built-in object area of the insertion section is the large-diameter section of the built-in article and the bending driving means. It is smaller than the case where the means overlap.

Embodiments Embodiments of the present invention will be described below with reference to the drawings.

1 to 7 relate to an embodiment of the present invention, FIG. 1 is an explanatory view showing the vicinity of a curved portion, FIG. 2 is a side view of an endoscope,
FIG. 3 is a longitudinal sectional view of the wire driving section, and FIG. 4 is A of FIG.
-A line sectional view, FIG. 5 is a circuit diagram showing a drive control circuit of the wire driving unit, FIG. 6 is an explanatory view showing a driving principle of a vibration wave motor used in the wire driving unit, and FIG. 7 is a vibration wave motor. FIG. 3 is an explanatory diagram showing the generation of a traveling vibration wave and a standing vibration wave in FIG.

As shown in FIG. 2, the endoscope 10 includes an elongated and flexible insertion portion 11, and a proximal end portion of the insertion portion 11 is connected to an operation portion 12. A flexible universal cord 13 is extended from the operation portion 12, and a connector 14 is provided at the tip of the universal cord 13. The insertion portion 11 is composed of a tip portion 15, a bending portion 16, and a flexible tube portion 17 from the tip side. Further, the operation portion 12 is provided with an eyepiece portion 18 continuously at the rear end portion, and on the side portion, an air / water supply switch 19, a suction switch 20, a bending operation switch 21 (DOWN), 22 (UP). , 23 (LE
FT), 24 (RIGHT), and a changeover switch 25 for switching between angle lock / free.

The tip portion 15 is provided with an objective lens system (not shown) and a light distribution lens. On the rear end side of the light distribution lens,
Light guides (not shown) are arranged in series. The light guide is inserted into the insertion portion 11 and the universal cord 13 and connected to the connector 14. By connecting the connector 14 to a light source device (not shown), the illumination light from the light source device is made incident on the incident end of the light guide. The illumination light is guided to the tip portion 15 by the light guide, is emitted from the tip of the light guide, passes through the light distribution lens, and is irradiated onto the subject. Further, the front end surface of the image guide 74 is arranged at the image forming position of the objective lens system. As shown in FIG. 1, the image guide 74 is inserted into the insertion portion 11 and extends to the eyepiece portion 18 side. The object image formed on the tip surface of the image guide 74 by the objective lens system is transmitted to the eyepiece 18 side by the image guide 74 and is observed from the eyepiece 18. There is.

As shown in FIG. 1, the bending portion 16 connects a joint piece 26 composed of a large number of short cylindrical tubular members so that the joint piece 26 can be rotated in a vertical direction indicated by an arrow a and a horizontal direction indicated by an arrow b. Is configured. That is, from each end face of each joint piece 26, a pair of connecting pieces 27 are circumferentially displaced by 180 degrees, and at each end surface, a pair of coupling pieces 27 are circumferentially displaced by 90 degrees, and are projected. Each pair of connecting pieces 27 of the adjacent joint pieces 26 is pivotally attached by a support shaft 28. The curved part
A connecting piece 27 is projectingly provided only on one end surface of the joint pieces 26a and 26b at the most distal end and the rearmost end of 16. Therefore, the bending portion 16 to which the joint piece 26 is connected is bendable in the vertical direction indicated by the arrow a and the horizontal direction indicated by the arrow b orthogonal to the vertical direction as described above.

On the inner peripheral surface of the most advanced joint piece 26a, cylindrical wire fixing portions 29 are provided at four positions which are displaced by 90 degrees in the circumferential direction corresponding to the bending direction of the bending portion 16. One end of the bending wire 30 is inserted into each through hole 29a of the wire fixing portion 29, and firmly fixed by soldering or the like. The other ends of the four bending wires 30 are provided on the inner peripheral surface of the joint piece 26b at 90 ° intervals, and are provided with four wire driving portions 31a as bending driving means.
It is pulled through into 31b, 31c, 31d (only 31b is not shown).
Then, the bending wire 30 and the wire driving unit 31 (31a, 31b, 31c,
On behalf of 31d). The joint piece 26 is curvedly driven by and.

The image guide 74 is housed in the insertion portion 11, and the image guide 74 in the bending portion 16 is an image guide.
A protective tube 75 is coated to prevent damage to 74. The entire length of the protective tube 75 is an arbitrary curved state, and the rear end of the protective tube 75 is the rear end of the joint piece 26b of the joint piece 2
It is set to be closer to the operation unit 12 than 7. Also, 4
The two wire drive parts 31 are
It is arranged with a certain distance in the axial direction from the rear end of 75. That is, the wire driving unit 31 is operated at a position closer to the operating unit 12 than the position where the outer diameters of the image guide 74 and the protection tube 75 are smaller.
It is located on the side.

Although not shown, a light guide and an air / water supply channel tube are inserted into the insertion portion 11 in addition to the image guide, and these built-in components may also be inserted as necessary.
The inside of the curved portion 16 is covered with a protective tube.

As shown in FIG. 3, the exterior part 32 of the wire drive part 31a is composed of a cylindrical pipe member, and the inner peripheral surface of the exterior part 32 is separated by approximately 90 degrees in the circumferential direction, and is fixed to four pieces along the entire axial length. A member 33 is provided. The fixing member 33 supports and fixes the fitting member 34 made of an elastic vibrating body from four directions. The fitting member 34 has a length that is substantially the same as the axial length of the exterior portion 32, and its circumferential cross section is substantially U-shaped. That is, the fitting groove 34a is provided in the axial direction. The two arms 34b of the fitting member 34 are inwardly slanted to each other, that is, slightly inclined toward each other, and sandwich the connecting rod 73, which is connected to the bending wire 30 by, for example, soldering, from both sides. Mating groove
The inner diameter of 34a is slightly smaller than the outer diameter of the connecting rod 73 in the natural state, and in the fitted state, the inner peripheral surface of the fitting groove 34a and the connecting rod 73 are fixed in close contact with each other. A large number of electrostrictive elements 35a and 35b are alternately bonded to the two opposing flat surfaces provided on the outer periphery of the fitting member 34 at intervals most suitable for generating a standing vibration wave described later. Has been done. Electrostrictive element 35a, 35
b is connected to the electric wires 36a and 37a, respectively. Also,
An electric wire 38a is connected to the fitting member 34. The other wire driving units 31b, 31c, 31d have the same configuration, and thus the description thereof will be omitted.

A control circuit as a control means for controlling each wire drive unit 31 will be described with reference to FIG. Switch control circuits 39 to 42 provided corresponding to the bending operation switches 21 to 24
Outputs a high level (H) / low level (L) voltage in conjunction with ON / OFF of each switch. Each output end of each switch control circuit 39 to 42 is a switch box.
It is connected to the control inputs of 43 to 46 and to the input of the OR circuit 47.

Switch control circuit provided for the changeover switch 25
48 outputs H level by the angle free operation and L level by the angle lock operation, and its output end is input to the input end of the OR circuit 47. The output terminal of the OR circuit 47 is connected to the control input terminal of the switch box 49.

The driving power source 50 supplies a voltage V = Vosinωt,
One end is connected to the electric wires 38a to 38d, and the other end is 90
Is connected to the input terminals of the phase shifter 51 and the input terminals of the switch boxes 43 to 46. The output ends of the switch boxes 43, 46, 44, 45 are the electric wires 36c, 36d, 36, respectively.
It is connected to a and 36b. The 90-degree phase shifter 51 advances the phase of the input voltage by 90 degrees, and its output end is connected to the input end of the switch box 49. The output end of the switch box 49 is connected to the electric wires 37a to 37d. The switch boxes 43 to 46 and 49 have a high voltage at the control input terminal.
When the level is L, the input terminal and the output terminal are electrically connected, and when the L level, the terminals are disconnected.

Here, the fitting member 34 of the wire driving unit, the bending wire 30
The operation principle of a vibration wave motor (also referred to as a piezoelectric motor, an ultrasonic motor, etc.) configured by the connecting rod 73 and the electrostrictive elements 35a, 35b connected to the above will be described by taking the wire drive unit 31a as an example.

In FIG. 6, 73 is a connecting rod as a moving body which is pressed by a force F, 34 is a fitting as a fixed body which elastically vibrates by an electrostrictive element (such as PZT) as an electric-mechanical energy converting means. It is the figure which showed the compound member typically, the X-axis is made into the direction on the surface of the fixed body 34, and the Z-axis is made into the normal line direction. When a bending vibration is applied to the surface of the fixed body 34 by the electrostrictive element, a traveling vibration wave is generated and propagates on the surface of the fixed body 34.
This traveling oscillatory wave is a surface wave accompanied by a longitudinal wave and a transverse wave, and the motion of its mass point draws an elliptical orbit. Focusing on the mass point A, an elliptic motion with a vertical deep movement u and a lateral amplitude w is performed, and when the traveling direction of the surface wave is the X-axis direction, the elliptic motion is a clockwise direction. This surface wave has vertices A, A '... for each wavelength,
The apex velocity is only the X component and is ν = 2πfu (f is the frequency). Therefore, when the surface of the moving body 73 is brought into frictional contact with the surface of the fixed body 34, the surface of the moving body 73 is apex A, A ′.
.., so that the moving body 73 is driven in the direction of arrow N by the frictional force.

The speed of the moving body 73 is proportional to the frequency f. Further, because of frictional drive by pressure contact, it depends not only on the longitudinal vibration u but also on the lateral vibration w. That is, the speed of the moving body 73 is proportional to the size of the elliptical movement. Therefore, the speed of the moving body 73 is proportional to the voltage applied to the electrostrictive element.

FIG. 7 is a diagram for explaining the generation of a traveling vibration wave and a standing vibration wave. When the electrostrictive elements 35a and 35b operate independently, the fixed body 34a
Are resonated, that is, they are arranged in a position where a standing vibration wave exists, and the standing vibration wavelength by the electrostrictive element 35a and the standing vibration wavelength by the electrostrictive element 35b become equal to each other, 90 degrees. They are arranged so that they are out of phase (the physical position is displaced by a quarter wavelength). The driving power supply 50 is V = Vosin
A voltage of ωt is supplied. Line 36a for electrostrictive element 35a
Thus, the voltage Vosinωt is directly applied from the driving power source 50, and the voltage Vosin (ωt ± π / 2) is applied to the electrostrictive element 35b through the 90-degree phase shifter 51 and the line 37a. Voltage Vosin
± of (ωt ± π / 2) is switched depending on the direction in which the moving body 73 is moved. (A) to (f) in FIG. 7 indicate the voltage Vosin.
The state of the vibration wave when (ωt + π / 2) is applied is shown. (A) is a state where a standing vibration wave is generated only by the electrostrictive element 35a, and (b) is 90 by only the electrostrictive element 35b.
3 shows a state in which a standing vibration wave with a phase advance is generated. (C) to (d) are two electrostrictive elements 35a, 35
It shows a state where the traveling vibration wave is generated by operating b simultaneously. (C) is time t = 0 + 2nπ / ω, (d) is time t = π / 2ω + 2nπ / ω, and (e) is time t = π / ω + 2n.
π / ω and (f) indicate the phases of the traveling vibration waves of 3π / 2ω + 2nπ / ω, respectively. Although the traveling oscillating wave travels to the left in FIG. 7, any mass point on the frictional contact surface of the fixed body 34 makes an elliptic motion in the clockwise direction. Therefore, the moving body 73 moves to the right.

In the generation state of the standing vibration waves of (a) and (b), lateral vibration occurs at the mass points other than the nodes on the frictional contact surface of the fixed body 34, that is,
It is only vertical movement in FIG. Therefore, the frictional contact between the moving body 73 and the fixed body 34 is not the static friction state but the dynamic friction state, the friction coefficient is small, and the contact area is also small. Therefore, the moving body 73 can be easily moved by an external force.

Next, the operation of this embodiment will be described. First of all, when the changeover switch 25 is angle-locked,
The case of UP operation will be described as an example. When the bending operation switch 22 (UP) is turned on, the switch control circuit 40 outputs the H level, so that the input / output terminals of the switch boxes 44, 49 are brought into conduction. As a result, a voltage V = Vosin ωt is applied to the electric wire 36a, and V = Vosin (ωt + π / is applied to the electric wires 37a to 37d.
2) is supplied. At this time, the electric wires 36b to 36
No voltage is supplied to d. Therefore, a standing vibration wave is generated in the fitting member 34 without the elastic vibrators of the wire driving units 31b to 31d, and the movable member can be easily moved by an external force. On the other hand, the fitting member 34 of the wire driving unit 31a has a connecting rod 7
A traveling frequency in the pulling direction of the wire 30 connected to 3 is generated. Therefore, the bending portion 16 bends smoothly in the UP direction by pulling the wire 30 in the UP direction. Then, when the bending operation switch 22 is turned off, no voltage is applied to the fitting members of the wire driving units 31, so that the wire driving unit 31 stops in the bending state and does not move easily even if an external force is applied to the bending unit.
Similarly, if the bending operation switches 21, 23, 24 are turned on, DO
Although curved in the WN, LEFT, and RIGHT directions respectively, description thereof will be omitted.

When the change-over switch 25 is operated in an angle-free manner, the switch control circuit 48 outputs an H level signal, so that the input / output terminals of the switch box 49 become conductive. Therefore,
V = Vosin (ωt
Since a voltage of + π / 2) is always applied, a standing vibration wave is always generated. In this state, for example, when the bending operation switch 22 is turned on, the bending operation is performed in the UP direction as in the angle lock operation described above.

When curved, the protective tube 75 of the image guide 74 is pulled toward the tip side, but its rear end surface does not move to the tip side from the connecting piece 27 of the joint piece 26b at the rear end. In addition, when the bending portion 16 and the flexible tube portion 17 are formed into arbitrary shapes, the protection tube 75 and the wire drive portion 31 do not interfere with each other due to the axial movement of the protection tube 75 of the image guide 74.

As described above, in the present embodiment, the wire driving unit 31 including the vibration wave motor is provided on the rear end side of the bending unit 16, and the bending unit 16 is driven to bend by the wire driving unit 31. Also,
An image guide 74 and the like are stored in the insertion portion 11, and the image guide 74 in the bending portion 16 is covered with a protective tube 75 in order to prevent damage to the image guide 74. Therefore, the outer diameter of the image guide 74 (and the protection tube 75) is thick inside the curved portion 16.

In the present embodiment, the wire driving section 31 is arranged with a certain distance in the axial direction from the rear end of the protective tube 75 in an arbitrary curved state. That is, the wire driving unit 31 is arranged closer to the operation unit 12 than the position where the outer diameters of the image guide 74 and the protection tube 75 are small.

Therefore, since the large-diameter portion of the image guide 74 covered by the protection tube 75 and the wire driving portion 31 do not overlap in any axial cross section of the insertion portion 11, the maximum internal component area of the insertion portion 11 does not exist. Is smaller than that in the case where the wire driving section 31 is provided at the rear end of the bending section 16 so as to overlap the protection tube 75, and the outer diameter of the insertion section 11 can be reduced.

Note that the present invention is not limited to the above-described embodiment, and for example, in the bending portion 16, the protective tube that protects the internal components of the insertion portion 11 is not limited to those that individually cover the image guide 74, the light guide, and the like. Instead, all the built-in components may be collectively covered.

Further, although the mounting switch 25 locks the upper / lower / left / right wire driving portions at the same time in the above-described embodiment, the upper / lower and left / right switches may be separate switches.

In addition, if the wire driving section is provided on both the tip forming section side and the hand operation section side and the bending wires are bent by pulling each other, quick bending is possible. Further, the electrostrictive element may be provided on the connecting rod (moving body) side instead of being provided on the fitting member (fixed body). A magnetostrictive element may be used instead of the electrostrictive element. Further, complicated bending can be performed by providing an appropriate number of bending portions of the above-described embodiment at appropriate portions of the endoscope insertion portion and operating them separately.

As described above, according to the present invention, the bending drive means is
Since the internal diameter of the insertion part is arranged closer to the operating part than the position where the operating part changes so that the operating part side has a smaller diameter, the external diameter of the inserting part is large even if the bending drive means is provided in the inserting part. There is an effect that can prevent.

[Brief description of drawings]

1 to 7 relate to an embodiment of the present invention, FIG. 1 is an explanatory view showing the vicinity of a curved portion, FIG. 2 is a side view of an endoscope,
FIG. 3 is a longitudinal sectional view of the wire driving section, and FIG. 4 is A of FIG.
-A line sectional view, FIG. 5 is a circuit diagram showing a drive control circuit of the wire driving unit, FIG. 6 is an explanatory view showing a driving principle of a vibration wave motor used in the wire driving unit, and FIG. 7 is a vibration wave motor. FIG. 3 is an explanatory diagram showing the generation of a traveling vibration wave and a standing vibration wave in FIG. 10 ... Endoscope, 11 ... Inserting part 12 ... Operating part, 16 ... Bending part 26 ... Joint piece, 30 ... Bending wire 31 (31a, 31b, 31c, 31D) ... Wire driving part 74 ... Image guide 75 ... Protective tube

Claims (1)

[Claims] 1. An insert section connected to an operation section is provided with a bendable bend section, and a bend drive means for bending the bend section is provided in the insert section, and at the same time, in the insert section. In an endoscope in which a built-in object whose outer diameter changes so that the operating portion side has a small diameter in the vicinity of the bending portion is housed, the bending driving means operates more than a position where the outer diameter of the built-in object changes. An endoscope characterized in that it is arranged on the side of the body.