JP3092980B2 - Endoscope - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an endoscope having driving means for bending a bending portion.

[0002]

2. Description of the Related Art Conventionally, endoscopes (scopes or fiberscopes) capable of diagnosing or examining internal organs and the like by inserting an elongated insertion portion into a body cavity have been widely used. I have. In addition, not only for medical use but also for industrial use, boilers, machines, chemical plants, etc.
Alternatively, it is used for observing and inspecting an object inside a machine or the like.

Further, various types of endoscopes using a solid-state image pickup device such as a charge-coupled device (CCD) as an image pickup means are also used.

In recent years, there has been proposed an endoscope which uses a motor as a driving means for a bending operation for bending a bending portion provided in an insertion portion of the endoscope, for example, up / down / left / right.

However, for example, the insertion portion of a medical endoscope is
When inserting through a curved part of the spleen, such as the large intestine, which has a large bending angle, simply pushing the insertion part only pushes the distal end side of the insertion part against the body cavity wall of the splenic curved part, making insertion difficult. Further, the distal end side of the insertion portion may be pushed back to the body cavity wall.

In order to advance the insertion section in the situation described above,
At the same time as changing the bending angle of the bending section from the bending state to the straight state, it is necessary to perform an operation of pushing the insertion section, and there is a disadvantage that the operation requires skill.

[0007]

As means for solving such a disadvantage, for example, the present applicant has disclosed in Japanese Patent Application Laid-Open No. 63-25 / 1988.
As disclosed in Japanese Patent Publication No. 2128, it has been proposed to use an outer skin having elasticity in the bending portion and to make the bending angle of the bending portion substantially straight using the elastic force of the outer skin.

However, in an endoscope using a motor as a driving means for bending the bending portion, even if the motor is stopped due to friction between the motor and the gear train, the bending portion is bent in a predetermined direction. Acts to be fixed as it is. Therefore, in order to set the bending angle to, for example, a predetermined angle at which the bending portion becomes substantially straight, there still remains a disadvantage that the lever must be operated so as to be bent in a direction opposite to the bending direction of the bending portion.

Further, in the endoscope using the motor as described above, when a momentary switch is used as the bending switch, the operator cannot easily recognize the bending angle of the bending portion, and Even if it has a bending angle display means for displaying a bending angle, it is necessary to instantaneously determine, for example, a bending direction in which the bending portion is set to a substantially straight state from the bending angle displayed on the bending angle display means. . Therefore, there is a disadvantage that skill is required.

[0010] To solve this problem, Japanese Patent Application No. Hei 2-8617 is used.
In 8, the first control means is controlled to be activated by the second control means, and the bending portion is brought into a substantially straight state. However, if the curved portion is in contact with the mucous membrane to force the straight state, there is a possibility that an excessive force may be applied to the mucous membrane, which involves a danger.

As another means for solving this, means for interposing a clutch between the motor and the indexing wire can be considered. In this case, if the clutch is disengaged, it returns straight due to the elasticity of the curved part outer skin, and since the elastic force is not so large, even if it is in contact with the mucous membrane, the curved part stops without applying excessive force to the mucous membrane . However, it is difficult to reduce the size of the clutch, which increases the size of the operation section and impairs the operability of the endoscope. The present invention has been made in view of the above circumstances, without using a clutch, there is no danger of applying excessive force to the test portion of the subject, for example, mucous membrane,
An object of the present invention is to provide an endoscope that can safely return an insertion portion straight.

[0012]

An endoscope according to the present invention comprises:
An insertion portion to be inserted into the subject, and a distal end side of the insertion portion.
In an endoscope having a bending portion provided, a bending operation instruction means for instructing a bending operation of the bending portion in a predetermined direction, and the bending portion in response to an instruction of the bending operation instruction means.
A drive means having a motor for curving drive, said motor
With a reaction force smaller than the friction force generated at rest
A bending portion constituting member forming the bending portion, and the driving means
State detecting means for detecting the bending state of the bending drive the bending portion, and a straight instruction means for instructing the return to the straight state of the bending portion, of the straight instructing means
The bending portion is straight with the bending portion based on the bending state detected by the state detecting means actuating said drive means in a direction that varies in a straight state in response to the instruction
Control means for stopping the operation of the driving means before returning to the state .

[0013]

With this configuration, the strain by the straight instructing means is provided.
The control means controls the driving means so that the bending portion moves in the direction changing to the straight state in response to the instruction to return to the straight state.
Activate. The control means is a state detection means.
The bending section is in a straight state based on the detected bending state
The operation of the drive means is stopped before returning to
I will .

[0014]

Embodiments of the present invention will be described below with reference to the drawings. FIGS. 1 to 4 relate to an embodiment of the present invention.
2 is a schematic overall configuration diagram of the endoscope apparatus, FIG. 2 is a flowchart of a straight return operation, FIG. 3 is a configuration diagram of a color filter, FIG. 4 is an explanatory diagram showing a relationship between an image area and noise, and FIG.
FIG. 4 is a waveform diagram for explaining noise suppression by driving a motor.

An endoscope apparatus 1 shown in FIG. 1 is for observing a portion to be inspected, and is an electronic endoscope 2 for outputting image signals.
And a light source CC for supplying illumination light to the electronic endoscope 2 and processing an image signal transmitted from the electronic endoscope 2.
U (camera control unit) device 3 and monitor 4 for displaying an image based on the video signal output from light source / CCU device 3
It is composed of

The electronic endoscope 2 has an elongated insertion portion 5,
An operation unit 6 of large diameter which is continuously provided at a rear end of the insertion portion 5, and a universality Le cable 7 extending from the side of the operation portion 6.

The insertion section 5 of the electronic endoscope 2 has, in order from the distal end, a hard distal end 8, a bendable bending section 9, and a flexible flexible section 10. The operation unit 6
Has a bending operation switch 11 as a bending operation instruction means.
And straight switch 3 as straight indicating means
0 is provided. By operating the bending operation switch 11, the bending portion 9 bends in the up / down / left / right directions.

The distal end 8 has an objective optical system 12 and an illumination optical system 13. A light guide 14 composed of a fiber bundle is provided continuously inside the illumination optical system 13. The light guide 14 is inserted through the insertion section 5, the operation section 6, and the universal cable 7, and is connected to the light source / CCU device 3. Then, illumination light emitted from a light source lamp (not shown) in the light source / CCU device 3 enters the incident end of the light guide 14 and is emitted through the illumination optical system 13.

Inside the objective optical system 12, an RGB filter 4 described later, which is rotated by a motor (not shown), is provided.
0, and a solid-state imaging device 15 such as a CCD that captures an image of the subject and converts the image into an electric signal is provided behind the RGB filter 40. This solid-state imaging device 15 includes:
The signal line 16 is connected, and the signal line 16 is inserted through the insertion unit 5, the operation unit 6, and the universal cable 7, and is connected to the light source / CCU device 3. And light source CC
The U device 3 drives the solid-state imaging device 15, performs signal processing on an electric signal output by the solid-state imaging device 15, and outputs a video signal. The monitor 4 displays an image based on a video signal from the light source / CCU device 3.

The bending portion 9 has a bending tube constituted by connecting a large number of substantially cylindrical joint pieces 20, 20... So as to be rotatable about a joint axis. Is covered with a curved outer skin 21 made of.

For example, two angle wires 22 (one not shown) for bending operation are inserted into the insertion portion 5, and the tips of the angle wires 22 are fixed to the tips 8, respectively. I have. In addition, a wire receiver (not shown) is provided at a predetermined interval on the inner peripheral portion of the joint piece after the second joint piece 20 from the distal end side, and an angle wire 22 is inserted into the wire receiver. Each angle wire 2
The two rear ends are wound around two pulleys (one not shown) 23 and folded back, and the front ends thereof are fixed to the front end 8 again through the curved tube.

The operation section 6 is provided with the bending operation switch 1.
1 and a straight switch 30 and a control circuit 24 for controlling the bending operation, two motors 25 (one not shown) as drive means driven by the control circuit 24 as control means, Two gears (one not shown) fixed to the rotating shaft of the motor 25, respectively
6 and two gears 27 meshing with each gear 26, respectively.
(One not shown), and the two pulleys 23 fixed to two shafts for fixing each gear 27, respectively. The operation unit 6 is disposed near the gears 26 and 27, is provided coaxially with the gear 26 or 27, and has two encoders 28 (one not shown) for measuring the number of rotations thereof. A counter 29 (one not shown) that counts pulse signals output from the encoders 28 and outputs a count value to the control circuit 24 is provided. A pair of the encoder 28 and the counter 29 constitutes a state detecting means.

That is, the encoder 28 and the counter 29
The rotation angle of the motor 25 is detected in combination with the above. If the relationship between the rotation angle of the motor 25 and the bending angle of the bending portion 9 is input to the control circuit 24, the bending angle of the bending portion 9 can be detected by the encoder 28 and the counter 29.

The two motors 25, gears 26 and 27,
One and the other of the pulley 23 and the angle wire 22 correspond to a vertical / left / right bending operation. The bending operation of the bending portion 9 is performed by the control circuit 24 driving the motor 25 in accordance with the operation amount of the bending operation switch 11,
The angle wire 22 is pulled and relaxed via the pulley 23 and the pulley 23, and bending is performed in the up / down / left / right directions.

The reaction force (return force) due to the elastic force of the curved outer cover 21 of the bending portion 9 is applied to the motor 25 and the gears 26 and 2.
7 has the following relationship with the frictional force. Friction force in a state where the motor 25 or the like is stationary> Reaction force of the curved outer cover 21 of the bending portion 9> Friction force in a state where the motor 25 or the like is moving.

The bending operation switch 11 can be operated two-dimensionally by a joystick type switch, and can instruct bending in four directions. Stick 11 of bending operation switch 11
The control circuit 24 performs control such that the inclination angle of “a” and the bending portion angle correspond one-to-one. The maximum bending angle differs in each direction (for example, 210 degrees in the upward direction, 90 degrees in the downward direction, and 100 degrees in each of the left and right directions), and the bending operation is performed by meeting the largest angle (210 degrees in the above example). The full scale (maximum tilt angle) of the stick 11a of the switch 11 is set. That is, when the step 11a of the bending operation switch 11 is tilted from neutral to, for example, an upward bending instruction direction, when the stick 11a is fully bent, the bending portion 9 is bent upward by 210 degrees. In addition, stick 11a
Is tilted downward from neutral, for example, in the direction in which the bending is instructed. When the stick 11a falls halfway,
The bending portion 9 bends at a lower maximum bending angle of 90 degrees.
Although the stick 11a further falls, the bending portion 9 does not move due to the operation of the control circuit 24. By setting the bending operation switch 11 and the control circuit 24 in this manner, it is possible to operate with the same operational feeling in each direction. For example, when the stick 11a is tilted by 5 degrees, the bending portion 9 bends by 45 degrees regardless of whether the stick 11a is tilted up, down, left, or right.

By providing a stopper in accordance with the setting of the bending angle, the stick 11a may be prevented from moving in the operation direction after the bending portion reaches the maximum bending angle. In this case, the operator can know from the change in the operation force amount that the curve is already maximum.

Further, in the bending operation switch 11, the stick 11a of the bending operation switch 11 is tilted to a position corresponding to the bending angle of the bending portion 9, so that the small motor 11b
Is provided. The control circuit 24 includes the encoder 2
The small motor 11b in the bending operation switch 11 is operated based on the information detected by the counter 8 and the counter 29. Thus, for example, when the power ON, the curved state of the bending portion 9, an accident resulting from the difference in the inclination angle of the stick 11a can be prevented. Incidentally, the power of the small motor 11b is smaller because the operator is adapted to not move when holding the stick 11 a of the bending operation switch 11.

The straight return operation will be described with reference to FIG. When the operator releases his / her finger from the bending operation switch 11 to turn on the straight switch 30, the bending portion 9 is set to the straight state according to the flowchart of FIG. This control is performed in the control circuit 24. In step (S) 1, the control circuit 24 checks the ON / OFF state of the straight switch 30 every predetermined time t1 (for example, 10 ms). When it is detected in step 2 that the control circuit 24 straight switch is ON, the bending angle of the bending portion 9 at that time is read from the output of the counter 29, and in steps 3 to 6, it is determined to which direction the bending portion is bent. I do. Then, the control circuit 24 controls the necessary motor 25 so that the bending portion 9 moves in the direction opposite to the bending direction determined in steps 7 to 10, that is, in the direction in which the bending portion 9 becomes straight.
Is driven for a time t2 (for example, 300 ms). Then, after holding for a time t3 (for example, 3 s) in step 11, ON / OF of the straight switch 30 in steps 1 and 2 is performed.
Return to the F detection loop.

The movement of the bending section 9 according to these flows will be described. When the straight switch 30 is off, the bending operation of the bending portion 9 is performed according to the instruction of the bending operation switch 11, and the bending portion 9 maintains the specified bending state. When it is detected that the straight switch 30 is ON and the motor 6 is driven for a time t2, the bending portion 9 starts to move in the straight direction. The drive of the motor 25 is t2
Although it ends in time, the bending portion 9 is further bent straight by the inertial force and the elastic force of the bending outer skin 21 of the bending portion 9. At this time, if there is something that restricts the movement of the curved portion 9 such as a mucous membrane, the bending portion 9 is stopped without applying a force higher than the inertial force and elastic force of the curved portion 9 to the mucous membrane or the like.

In this embodiment, a straight switch 30 is provided which is operated when the bending section 9 is desired to be in a straight state.
Detects the bending direction of the bending portion 9 by the encoder 28 and the counter 29, and drives the motor 25 for a predetermined period of time so as to bend the bending portion 9 in a direction opposite to the detected bending direction, and then stops. In the stopped state, the motor 25 and the gear 2 are smaller than the elastic force of the curved outer skin 21 of the bending portion 9.
Since the frictional force (static friction) is larger, the curved portion 9
Remains stopped. Then, one Dan when the bending portion 9 starts moving, the motor 2 than the elastic force of the curved outer skin 21 of the bending portion 9
5 and the frictional force (dynamic friction) of the gears 26 and 27 are smaller
As a result, the bending portion 9 is in a straight state.

Since the straight section is not forcibly straightened, if it comes into contact with the mucous membrane, the bending section 9 stops without applying an excessive force to the mucous membrane. Thus, in this embodiment, the straight return operation can be performed without applying excessive force to the mucous membrane of the subject.

In the next t3 time, the straight switch 30
Is turned off, normal operations can be performed thereafter. When the straight switch 30 is kept ON, the driving for the time t2 for returning to the straight state is repeated once again.

As the state detecting means for knowing the bending state of the bending portion 9, means for detecting the tension of the ang wire 22 with a strain gauge or the like, or means for directly detecting the bending direction of the bending portion 9 with a strain gauge or the like is used. You may. Although the electronic endoscope has been described as an example in the illustrated example, the present invention can be applied to an optical fiber endoscope.

The electronic endoscope 2 irradiates illumination light supplied by the light source / CCU device 3 from the distal end 8 of the endoscope to the observation object via the light guide 14. The reflected light from the observation object is received by the solid-state imaging device 15 at the end of the endoscope,
Light source / CCU device 3 via signal line 16 as an electric signal
The monitor 4 projects the observation object, for example, the surface of the mucous membrane of the organ. The illumination light from the CCU device 3 of the light source is R
The signal transmitted through the GB filter 40 is processed as a so-called frame sequential method.

As shown in FIG. 3, the RGB filter 40 is substantially divided into four, three of which are R, G, and B filters, respectively, and the other one is a shielding part 40a.
Then, in response to an instruction from the bending operation switch 11 or the straight switch 30, a drive signal (for example, a pulse) for driving the motor 25 is output in synchronization with the shielding section 40a of the RGB filter 40 facing the light source. Is done. Therefore, the drive pulse output to the motor 25 is
No noise is generated in the output signal of solid-state imaging,
The monitor 4 also displays an image without noise.

In the illustrated example, the motor 25 for bending is shown as an example with respect to the noise countermeasures. However, other than the above, the bending motor 25 used for an endoscope may be used for standing up, autofocusing, autozoom, ultrasonic observation, and so on. A similar configuration is possible for all motors for treatment and the like.

As another method for preventing the influence of noise, as shown in FIGS. 5A to 5C, a motor driving pulse is synchronized with a horizontal or vertical synchronizing signal of an output signal of the solid-state imaging device 15. And control so that the rising edge and the falling edge of the driving pulse are within the vertical or horizontal blanking period (the blanking period is composed of the blanking pulse and the front and back porch portions before and after the blanking pulse). You may. Alternatively, when the motor 25 is a pulse motor, as shown in FIG.
While the switch is ON, a drive pulse may be generated every blanking period.

Further, not all of the pixels of the solid-state imaging device 15 are used for an image. For this reason, as shown in FIG. 4, it can be divided into a region (region A) in which noise is not desired to be used as an image and a region (region B) in which noise does not affect the image even if noise is present. Therefore, if the motor drive pulse is generated in synchronization with the time for transferring the area B, the influence of noise on the image can be prevented. Further, as another method, the frequency of the synchronous clock for transfer is doubled to generate a video signal every other frame, and the signal of the frame between the frames is discarded. If the motor drive pulse is generated in synchronization with the time for transferring the signal of the discarded frame, the influence of noise can be prevented.

[0040]

As described above, according to the present invention, there is no danger of applying an excessive force to a test portion of a subject, for example, a mucous membrane, without using a clutch, and a straight return operation can be performed safely. There is an effect that can be.

[Brief description of the drawings]

FIG. 1 is a schematic overall configuration diagram of an endoscope apparatus.

FIG. 2 is a flowchart of a straight return operation.

FIG. 3 is a configuration diagram of a color filter.

FIG. 4 is an explanatory diagram showing a relationship between an image area and noise.

FIG. 5 is a waveform diagram for explaining noise suppression by driving a motor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 2 ... Electronic endoscope 5 ... Insertion part 6 ... Operation part 8 ... Tip part 9 ... Bending part 11 ... Bending operation switch 20 ... Bending piece 21 ... Bending outer skin 22 ... Angle wire 24 ... Control circuit 25 ... Motor 26, 27 ... Gear 28 ... Encoder 29 ... Counter 30 ... Straight switch

Claims (1)

(57) [Claims] An endoscope having an insertion portion inserted into a subject and a bending portion provided at a distal end side of the insertion portion, wherein the bending operation of the bending portion in a predetermined direction is performed. a bending operation instruction means for instructing, in response to an instruction of the bending operation instruction means, bay the curved portion
A driving means having a motor for driving the bending, and a reaction force smaller than a friction force generated when the motor is stationary
A bending portion constituting member having a force to configure the bending portion; a state detection unit detecting a bending state of the bending portion driven to be bent by the driving unit; and an instruction to return the bending portion to a straight state. a straight instruction unit that, in response to an instruction of the straight instruction means, based on the curved state detected by the state detecting means, actuating said driving means in a direction in which the bending portion is changed to a straight state
Before the bending portion returns to the straight state.
An endoscope comprising: control means for stopping the operation of the driving means .