JP5253852B2 - Endoscope bending section drive device - Google Patents

Description

  The present invention relates to an endoscope bending portion driving apparatus suitably used as a colonoscope or the like in which an insertion path of an insertion portion is bent in a complicated manner and a large resistance acts on the insertion portion.

  A colonoscope as a kind of endoscope is inserted through the anus from the anus. This insertion part leads from the rectum through the sigmoid colon to the descending colon, and further into the transverse colon. It is possible to progress through the transverse colon to the ascending colon, more preferably to the cecum. Of these insertion paths, the sigmoid colon is a complex path having a three-dimensional loop, and the transition part from the sigmoid colon to the descending colon has an extremely bent structure. Moreover, when the insertion portion is moved while sliding on the intestinal tract wall, the intestinal tract wall easily expands and contracts according to the movement. From the above, it is difficult to insert the insertion portion into the insertion path, and high skill is required.

  In order to pass through the sigmoid colon, a considerably complicated operation such as twisting the insertion portion, looping, and reciprocating back and forth must be performed. However, the sigmoid colon is a site where the insertion depth of the insertion portion is shallow, and it is not so difficult to exert an operating force on the distal end of the insertion portion. On the other hand, in the case where the deep part of the large intestine is the subject of the examination, even if the sigmoid colon is passed through, the transition part from the sigmoid colon to the descending colon, the transition part from the descending colon to the transverse colon, If the bent part that reaches one after another is not passed, it is not possible to reach the site to be examined.

  The deeper the insertion depth of the insertion portion, the more constricted the anus and the passage of the tortuous sigmoid colon become the obstacle to the transmission of the operation force of the pushing operation, and the operation from the outside to the insertion portion The force may not reach the tip accurately. In addition, the insertion portion and the intestinal tract wall may be in close contact with each other, and further advancement may not be possible. As described above, when the insertion portion is in a state in which it is difficult or impossible to proceed, a great deal of pain is imposed on the subject, and the operability of the endoscope also deteriorates. Furthermore, there is a possibility that the directionality of the insertion portion in the insertion direction may be mistaken, and the bent portion may not be smoothly passed.

From the above, in Patent Document 1, a vibration member is provided inside the connecting portion between the bending portion and the soft portion of the insertion portion, and the vibration member is operated to strike the side surface of the insertion portion in the vicinity of the tip. Thus, there is disclosed a technique in which the sticking state between the insertion portion and the intestinal tract wall, that is, the stick state is released by applying vibration. Patent Document 2 discloses a configuration in which the hardness in the bending direction of the insertion portion is changed according to the operation mode. In Patent Document 2, a tightly wound coil fixed to a proximal end portion of a flexible tube in a soft portion is extended toward the distal end side of the soft portion, and a wire is inserted into the coil. An endoscope having a configuration in which a coil is brought into close contact with each other by pulling and a part of a soft part is hardened is disclosed.
JP 2004-209271 A JP 2002-355217 A

  As described above, if the side near the distal end of the insertion portion is vibrated, the insertion portion can be improved in insertion operability even if the insertion portion can be eliminated to some extent from the intestinal wall. is not. For example, in the large intestine, when passing through an extreme bending portion such as a transition portion from the sigmoid colon to the descending colon and a transition portion from the descending colon to the transverse colon, some vibration is generated at the distal end side of the insertion portion. Even if given, may not be able to promote the passage. In addition, the progress of the insertion part is not only due to the close contact of the insertion part with the intestinal wall, but also the problem of how to select the path. May not be able to proceed smoothly in the intestinal tract. In addition, although it is meaningful for the insertion operation to vibrate the insertion portion, providing a driving means for generating vibration inside the distal end portion of the insertion portion makes the insertion portion unnecessarily thick. However, this is not desirable in that the configuration is complicated.

  Moreover, in the structure of patent document 2, the hardness of an insertion part can be changed suitably in the state which inserted the insertion part in the body cavity tube | pipe. However, the operation of inserting into the path having a complicated structure such as the insertion path of the colonoscope cannot be smoothly performed only by making it possible to control the hardness of the soft part of the insertion part. When the intestinal tract wall is moved while sliding the insertion portion as the body cavity wall, the intestinal tract wall easily expands and contracts according to the movement. Therefore, if the soft part in the insertion part is hardened and pushed into the intestinal tract, this pushing force is transmitted to the distal end of the insertion part, and the insertion part advances, but at the same time, the intestinal tract wall is inserted into the insertion part. The intestinal tract wall is pushed toward the front side as the insertion portion advances. For this reason, even if the insertion part is hardened, the body cavity tube wall into which the insertion path is pushed in becomes jammed and obstructs the forward part of the course, preventing further progress of the insertion part. Become.

  By the way, the insertion portion of the endoscope is composed of a soft portion, a bending portion, and a hard tip portion in order from the connection side to the main body operation portion, and the bending portion can be bent by a remote operation from the main body operation portion. The bending portion driving device that drives the bending portion has a rotation operation member including a knob, a lever, or the like provided in the main body operation portion as its operation means. Further, a pulley is connected to the rotation operation member, and an operation wire is wound around the pulley. The operation wire is guided into the insertion portion and fixed to the distal end of the bending portion or the distal end hard portion. A pair of operation wires are provided, and when the bending portion is bent in an arbitrary direction, a pair of operation wires are provided on the upper and lower sides and the left and right sides, and two pulleys are provided. When the turning operation member is turned, the pulley is turned. One of the two operation wires wound around the pulley is taken up, and the other is rewound. A pulling force acts on the operation wire wound around the pulley, and the bending portion is bent.

  The bending portion is connected to the distal end hard portion, and if the bending portion is reciprocally bent, a swinging operation can be performed. In addition, a soft portion is connected to the base end portion of the curved portion, and the soft portion has flexibility in the bending direction. Furthermore, the soft portion has elasticity, and when the swinging motion of the curved portion is performed, a force that tries to be straight acts. Furthermore, when the action of the external force is released from the state in which the soft part is bent by the external force, the elastic force acts so as to be in a straight state.

  Therefore, while the insertion portion is inserted into the insertion path, the body cavity tube wall is pushed into the outer surface of the insertion portion so that the body cavity tube wall is pushed in, which hinders the progress of the insertion portion. Even if the progress of the hard part is hindered, the soft part meanders when the insertion part is pushed into the path. If the front part of the insertion part is opened from this state, the insertion part repels and moves forward by the amount of meandering as an expansion allowance in which the meandering part of the soft part is accumulated. Just by vibrating inside the distal end portion of the insertion portion as in the prior art described above, the front part of the body cavity wall cannot be opened, but it was pushed in if the distal end portion of the insertion portion was swung. The body cavity wall returns to the original position, and the front of the insertion path can be opened. In this case, the swinging motion of the insertion portion is more effective when the angle of the reciprocating bending motion of the bending portion is increased to some extent.

  However, the reason why the bending portion is provided in the insertion portion is not for performing the above-described swinging operation, but originally for controlling the direction of the distal end hard portion, that is, for performing a direction control operation. This direction control operation is for making sure that the distal end of the insertion portion advances toward the desired insertion path when the insertion portion is inserted along the bent insertion path. Curved in the direction. In addition, since the distal end hard portion is provided with the endoscope observation means, the direction control operation for bending the bending portion is performed even when the observation visual field is changed.

  Thus, when controlling the direction of the distal end hard portion, in order to improve operability, it is desirable to suppress the ratio of the bending angle of the bending portion with respect to the bending operation amount by the rotating operation member to be small. If the bending portion is greatly bent with a small bending operation amount, the direction of the distal end of the insertion portion cannot be finely controlled. On the other hand, as described above, when swinging the distal end portion of the insertion portion in order to advance to the insertion path, it is desired that the insertion portion is greatly swung with a small angle of the rotation operation member. .

  Therefore, an object of the present invention is to maintain high controllability when controlling the direction of the distal end portion of the insertion portion when bending the bending portion, and to have operability for swinging operation during insertion. An object of the present invention is to provide a bending section driving device for an endoscope which has been improved.

In order to achieve the above-described object, the present invention provides a main body operation unit with an insertion unit composed of a soft part, a bending part, and a distal end hard part, and the bending part is bent by remote operation from the main body operation part. A bending portion driving apparatus for an endoscope that includes a rotation operation member by manual operation and a rotation angle detection member that detects a rotation angle of the rotation operation member. A bending operation means; at least a pair of operation wires coupled to the distal end portion of the bending portion or the distal end hard portion; and a pulley provided in the main body operation portion and provided by winding the proximal end side of each operation wire. A bending operation means having a rotation drive member for rotating the pulley, and the bending operation means according to the rotation angle of the rotation operation member detected by the rotation angle detection member of the bending operation means. Rotating drive member And control means for,
The input / output ratio adjusting means for changing the ratio between the rotation angle detection signal from the bending operation means and the rotation angle of the pulley by the rotation drive member, and the bending portion according to the operation by the rotation operation member. The direction control operation mode in which the bending portion is bent at an appropriate bending angle to direct the distal end hard portion in the intended direction, and the rotation operation in the direction control operation mode in order to swing the bending portion. It is characterized by comprising a switching member that can be switched to a bending angle amplification operation mode for bending at a larger angle than when the member is operated .

  As the bending operation means for driving the bending portion in the insertion portion, the pulley is not directly operated by the rotation operation member constituting the bending operation means, but is driven by the rotation driving member composed of an electric motor, an ultrasonic motor or the like. It is configured to drive based on the control signal from the control means. Thereby, the relationship between the operation amount of the rotation operation member and the rotation angle of the pulley can be arbitrarily changed. Then, the ratio between the rotation angle detection signal from the bending operation means and the rotation angle of the pulley by the rotation drive member is changed by the input / output ratio adjustment means. This change is made in two stages or more. Further, it can be configured to change steplessly.

  With respect to the rotation angle detection means input from the bending operation means to the control means, at least the bending angle of the bending portion when operating in the direction control operation mode and the bending of the bending portion when operating in the bending angle amplification operation mode Different from the corner. In the direction control operation mode, in order to control the direction of the distal end of the insertion part with high accuracy, the ratio of the rotation angle (output amount) of the pulley to the operation amount (input amount) of the rotation operation member is made small. Set the output ratio. On the other hand, in the bending angle amplification operation mode, the input / output ratio is set so that the output amount is large with respect to the small input amount. Accordingly, it is possible to accurately control the direction of the distal end of the insertion portion by operating in the direction control operation mode during a normal insertion operation. Further, when swinging the distal end portion of the insertion portion to advance to the insertion path, when switching to the bending angle amplification operation mode, the bending portion is reciprocally rotated by a small angle, thereby turning the bending portion. Can be greatly curved. This makes it possible to perform an appropriate bending operation according to the insertion mode of the insertion portion.

  In the direction control operation mode, the latter is finer for the operation of guiding the distal end of the insertion section along the insertion path and the operation of changing the direction of the observation field when observing the inside of the body cavity. Need to control. Thus, in the direction control operation mode, the input / output ratio can be changed in two stages. Also, during operation in the bending angle amplification operation mode, the angle of the reciprocal bending angle of the bending portion between the part where the insertion path is extremely bent and the other part and due to the space of the insertion path It may be desirable to change Therefore, the input / output ratio can be switched in a plurality of stages even in the bending angle amplification operation mode. Furthermore, when the input / output ratio is changed steplessly including the direction control operation mode and the bending angle amplification operation mode, optimum characteristics can be obtained according to the individuality of the operator who operates the endoscope. It becomes like this.

  In general, the bending portion includes a configuration that bends in two directions, for example, an up-down direction, and a configuration that can be bent in four directions, up-down and left-right. When the configuration is such that the operation wire can be bent in four directions, the operation wire is provided at four positions at an angle of approximately 90 degrees, with different positions in the circumferential direction of the bending portion, and pulleys around which the operation wires are wound are provided. Two are provided. Further, the rotation operation member is individually provided for each pulley. The input / output ratio can be changed by both pulleys or one of the pulleys. When operating in the bending angle amplification operation mode based on the posture of the subject into which the endoscope is inserted and the posture of the operator who performs the operation, it is desirable to use a pulley for bending operation in the vertical direction. In this case, the other pulley, that is, the pulley for bending in the left-right direction, can be configured to be directly rotated by the rotation operation member, or may be a pulley driven by the rotation drive member.

  In performing the bending operation of the bending portion, it is possible to maintain high controllability when performing the direction control of the distal end portion of the insertion portion, and to perform the swinging operation easily and smoothly.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. First, FIG. 1 shows a schematic configuration of an endoscope, and FIG. 2 shows a schematic configuration of a mechanism for bending the bending portion. In the figure, 1 is a main body operation unit, 2 is an insertion unit, and 3 is a universal cord. The insertion portion 2 is a flexible portion 2a that bends in an arbitrary direction along the insertion path for most of the length from the side connected to the main body operation portion 1, and a bending portion 2b is formed at the tip of the flexible portion 2a. Further, a distal end hard portion 2c is provided at the distal end of the curved portion 2b. Although not shown in the drawings, the distal end surface of the distal end hard portion 2c is provided with an endoscope observation means including an illumination portion and an observation portion, and allows a treatment instrument to be inserted and an operation such as suction of filth in the body. The treatment instrument insertion passage for performing is opened. The bending portion 2b is configured to allow a bending operation in order to direct the distal end hard portion 2c in a desired direction. The bending direction of the bending portion 2b is four directions, that is, a vertical direction and a horizontal direction. It should be noted that the bending direction can be limited to two directions, ie, the vertical direction.

  The bending operation of the bending portion 2 b of the insertion unit 2 is performed by remote operation from the main body operation unit 1. For this purpose, a bending drive means 10 for bending the bending portion 2b is provided in the main body operation unit 1. The main body operation unit 1 is provided with a bending operation means 20. The bending operation means 20 can be operated with a finger of a hand holding the main body operation unit 1 and constitutes an input means for bending operation. On the other hand, the bending drive means 10 drives the bending portion 2b to bend according to the rotation angle of the bending operation means 20 as input means, and functions as output means.

  FIG. 2 conceptually showing the configuration of the bending driving means 10 shows a mechanism for driving the bending portion 2b to bend in the vertical direction. In addition, in reality, a similar mechanism is provided in a direction orthogonal to this so that the bending portion 2b can be bent in the left-right direction. However, the illustration and detailed description of the mechanism for driving the bending in the left-right direction are omitted. ing. In the following description, in order to distinguish between a member that drives bending in the vertical direction and a member that drives bending in the left-right direction, “UD” is used for the former and “LR” is used for the latter after the reference numerals of the respective members. Subscripts shall be attached.

  The bending portion 2b of the insertion portion 2 is configured by sequentially pivoting the node rings 4, and when the configuration is such that the front and rear node rings 4 and 4 can be bent vertically and horizontally, It is pivoted alternately with the top and bottom. A pair of upper and lower operation wires 11, 11 are connected to the node ring 4a, which is located at the forefront of the curved portion 2b and connected to the distal end hard portion 2c. Both the operation wires 11 and 11 are extended from the bending portion 2b to the inside of the main body operation portion 1 through the flexible portion 2a, and are wound around a pulley 12 provided in the main body operation portion 1. Accordingly, when the pulley 12 is rotated in the arrow RU direction in FIG. 2, the bending portion 2b is bent in the arrow BU direction, and when the pulley 12 is rotated in the arrow RD direction, the bending portion 2b is bent in the arrow BD direction. . The operation wire 11 moves back and forth while being positioned in the circumferential direction in the bending portion 2b, and is inserted into the closely wound coil 13 in the flexible portion 2a.

  The pulley 12 is connected to an ultrasonic motor 14 as a rotation driving means. As shown in FIG. 3, the ultrasonic motor 14 is a traveling wave type ultrasonic motor having a structure in which a stator 14b is attached to a piezoelectric vibrator 14a and a slider 14c is pressed against the stator 14b. A plurality of the piezoelectric vibrators 14a are polarized. When an AC voltage is applied to the piezoelectric vibrators 14a, the piezoelectric vibrators 14a perform expansion / contraction movement for each zone, and elastic bending waves are generated. As a result, the slider 14c moves due to the frictional force generated between the stator 14b and the slider 14c. The slider 14c moves in the direction of arrow A or arrow B in the figure depending on the voltage application order. Therefore, the pulley 12 is connected so as not to rotate relative to the slider 14c of the ultrasonic motor 14. As a result, one of the pair of operation wires 11 and 11 is wound around the pulley 12 to generate tension, and the other is pulled out from the pulley 12, and the bending portion 2 b is on the side on which the tension in the operation wire 11 acts. Curving towards.

  Next, as shown in FIG. 4, the bending operation means 20 has operation knobs 21UD and 21LR arranged above and below the main body operation unit 1, and these operation knobs 21UD and 21LR are respectively connected to the outer shaft 22 and The outer shaft 22 and the inner shaft 23 are coaxially connected to the inner shaft 23. Therefore, when the operation knob 21UD is operated, the outer shaft 22 is rotated according to the operation amount, and when the operation knob 21LR is operated, the inner shaft 23 is rotated according to the operation amount. Will do.

  The outer shaft 22 and the inner shaft 23 are extended in a rotation angle detection unit 24 provided inside the casing 1a of the main body operation unit 1. In the rotation angle detection unit 24, encoder plates 25UD and 25LR are arranged vertically as rotation angle detection members, and the angles of the encoder plates 25UD and 25LR are detected by the optical sensors 26UD and 26LR. Yes. The outer shaft 22 and the inner shaft 23 are provided with urging means 27, 27 shown in FIG. 5 in order to return to the neutral position. The urging means 27 is composed of spiral springs 27a and 27b wound in opposite directions, and these spiral springs 27a and 27b are wound in opposite directions.

  Therefore, when the operation knob 21 constituting the bending operation means 20 is not operated, the biasing forces of the two spiral springs 27a and 27b are held at a balanced angular position, which is a neutral position, that is, a position where the bending portion 2b is in a straight state. It is. When the operation knob 21 is rotated in either direction from this neutral position, one of the spiral springs 27a or 27b is wound, and the urging force is accumulated according to the amount of winding, so that the operation knob 21 is operated in reverse. Force is generated. At this time, since the other spiral spring is rewound, no urging force is accumulated. Accordingly, when the operation force applied to the operation knob 21 is released, the state returns to a state where the urging forces of the two spiral springs 27a and 27b are offset. In this state, the bending portion 2b is set to be straight.

  When the operation knob 21UD or 21LR of the bending operation means 20 is operated, the ultrasonic motor 14UD or 14LR constituting the bending drive means 10 is operated to rotate the pulley 12, and the pair of operation wires 11 and 11 are wound and wound. A return is made. For example, in FIG. 2, when the operation wire 11 provided above is wound, the wound operation wire 11 is pulled, and the upper gap between the front and rear node rings 4 and 4 is reduced. The gap on the lower side is increased, and the bending portion 2b is bent upward.

  Therefore, as shown in FIG. 6, a controller 30 is provided as a control means. The controller 30 includes optical sensors 26UD and 26LR that detect the rotation angles of the encoders 25UD and 25LR in the rotation angle detector 24. The rotation angle detection signal is taken as an input signal. Then, the ultrasonic motors 14UD and 14LR are operated by the output signal from the controller 30 to control the pulleys 12UD and 12LR to rotate, but the pulley 12UD for bending the bending portion 2b in the vertical direction is controlled. The ratio of input / output signals is assumed to be variable. For this purpose, an input / output ratio setting device 31 is connected to the controller 30, and an operation knob 32 is connected to the input / output ratio setting device 31, and based on a signal from the input / output ratio setting device 31. The ratio of the output signal to the ultrasonic motor 14UD changes with respect to the input signal from the rotation angle detector 24 in the controller 30. The input / output ratio in the input / output ratio setting unit 31 can be adjusted by the operation knob 32.

  In the input / output ratio setting unit 31, the ratio of the output signal to the ultrasonic motor 14UD with respect to the input signal from the rotation angle detection unit 24 is set to an input / output ratio in the direction control operation mode and an input / output ratio in the bending angle amplification operation mode. It is comprised so that it may change in two steps. The operation knob 32 described above also functions as a mode switching means for driving the bending portion 2b to bend in any operation mode.

  The direction control operation mode is an operation mode in which a normal bending operation is performed in which the bending portion 2b is bent in an appropriate manner in order to perform an operation of directing the distal end hard portion 2c in the insertion portion 2 in a desired direction. On the other hand, in the bending angle amplification operation mode, when the body cavity tube wall located in front of the distal end hard portion 2c of the insertion portion 2 covers the front in the insertion direction, the distal end hard portion cannot be further advanced. This is an operation mode for performing an operation of reciprocating up and down in order to swing the 2c and move it forward and move forward. Accordingly, when the bending portion 21UD is rotated by a certain angle, a larger angle than the bending angle of the bending portion 2b that operates during the operation in the direction control operation mode, and more specifically during the operation in the bending angle amplification operation mode, Will be curved several times. Note that the bending angle amplification operation mode can be operated only when the bending operation is performed in the vertical direction. When performing the bending operation in the horizontal direction, the operation mode cannot be selected, and the direction control operation is always performed. Operation in the mode is to be performed.

  The endoscope having the above configuration is suitably used as a so-called colonoscope when the insertion portion 2 is inserted into the large intestine. That is, as shown in FIG. 7, the insertion section 2 is inserted from the anus 40, reaches the descending colon 43 through the rectum 41 through the sigmoid colon 42, and is further guided into the transverse colon 44. It is possible to advance through 44 to the vicinity of the ascending colon 45, more preferably the position of the cecum 46.

  The sigmoid colon 42 has a three-dimensional loop structure, and the insertion operation is difficult. However, since the insertion position is shallow, the insertion portion 2 is looped or reciprocated back and forth. Although the operation is necessary, it is possible to control the distal end of the insertion portion 2 and to advance the insertion portion 2 along the insertion path. Therefore, the direction control operation mode is set until the sigmoid colon 42 is passed. When the operation knobs 21UD and 21LR constituting the bending operation means 20 are operated, the operation amount signal detected by the rotation angle detection unit 24 is input to the controller 30. The pulleys 12UD and 12LR are rotated based on the output signal from the controller 30, and the bending portion 2b is bent by an angle corresponding to the operation amount in the operated direction. As a result, the distal end portion of the insertion portion 2 advances while following a path that is bent in an arbitrary direction. In addition, since the bending operation is performed in the direction control operation mode, the bending angle of the bending portion 2b is relatively small with respect to the operation of the operation knobs 1UD and 21LR, so that the direction of the distal end portion of the insertion portion 2 is accurately determined. Can be controlled.

  When the distal end hard portion 2 c of the insertion portion 2 passes through the sigmoid colon 42, it enters the descending colon 43 and then heads toward the transverse colon 44. Since the insertion portion 2 passes through the narrowed portion called the anus 40 and is bent in a complicated manner in the sigmoid colon 42, even if the operation is performed to push in the proximal end portion of the insertion portion 2, the insertion path The pushing force may not be transmitted to the tip part that reaches the deep part of the. In addition, since the intestinal tract wall having a large stretchability is pushed out, the resistance of the insertion portion 2 is greatly increased. As a result, the soft portion 2a of the insertion portion 2 that is flexible in the bending direction meanders with the distal end portion of the insertion portion 2 in close contact with the intestinal tract wall due to resistance against pushing. Then, as indicated by the solid line in FIG. 8, the length of the inserted portion is absorbed by meandering in the middle, and the distal end hard portion 2 c constituting the distal end portion of the insertion portion 2 is locked, and further proceeds. No longer. In particular, the transition from the descending colon 43 to the transverse colon 44 and the transition from the transverse colon 44 to the ascending colon 45 are extremely curved, and it is extremely difficult to pass these parts.

  Therefore, the operation knob 32 is operated to set the bending angle amplification operation mode. When the insertion portion 2 is advanced to a certain extent, the distal end hard portion 2c is in a locked state, and when the vicinity of the distal end of the flexible portion 2a is in a meandering state, the suction mechanism of the endoscope is used to enter the intestinal tract. It is made into a collapsed state by sucking and discharging the air. Thereby, the site | part of the sigmoid colon 42 of the insertion part 2 will closely_contact | adhere with an intestinal tract wall, and the movement to the direction opposite to an insertion direction, ie, a reverse motion, is controlled.

  In order to further advance the insertion portion 2 under the above circumstances, the operation knob 21 is operated to rotate in the vertical direction of the FNP using the large intestine FNP (Fine Network Pattern) as an index. For example, the operation knob 21UD is operated to reciprocate and the bending portion 2b located near the distal end of the insertion portion 2 is bent upward (downward) frequently and to some extent quickly. As a result, the distal end portion of the insertion portion 2 swings. By this swinging operation, the outer surface of the insertion section 2 is separated from the intestinal tract wall, and the intestinal tract wall pushed in the moving direction of the insertion section 2 returns to the original position, thereby opening the front of the insertion path. Further, by performing the bending (swinging) operation of the bending portion 2b, the flexible portion 2a tends to be in a straight state. At this time, since the reverse movement of the insertion portion 2 is restricted, the loop portion tends to straighten. As a result, the locked state of the distal end hard portion 2c is released, and the tip portion advances while the meandering state is released by the action of the elastic force of the insertion portion 2 as shown by the phantom line in FIG. At this time, the surgeon grasps the proximal end portion of the insertion portion 2 but does not need to operate it in the direction of pushing it.

  In this way, by repeating the pushing of the insertion portion 2 and the subsequent swinging motion of the bending portion 2b, the insertion portion 2 having advanced to the deep part of the large intestine advances smoothly and reliably. In addition, since the head moves forward while searching for the path to be inserted, the flexion is a transition part from the descending colon 43 to the transverse colon 44b or a transition part from the transverse colon 44 to the ascending colon 45. It will pass smoothly through the part.

  The swinging motion of the distal end of the insertion portion 2 is performed by reciprocatingly rotating the operation knob 21UD. In order to improve the operability, the bending portion 2b is enlarged with a small rotation operation angle of the operation knob 21UD. Curve back and forth. This is why the bending operation mode is set to the bending angle amplification operation mode. As a result, when the operation knob 21UD is reciprocatingly rotated with the finger of the hand holding the main body operation unit 1, the bending portion 2b has a large angle with a small operation amount, that is, the input / output ratio is smaller than that in the direction control operation mode. It will be curved at double the size. Therefore, the operation of releasing the adhesion between the insertion portion 2 and the intestinal tract wall and moving forward becomes extremely easy, and the burden on the operator is reduced.

  As described above, the insertion portion 2 smoothly proceeds in the colon, and when the distal end hard portion 2c is inserted to a position to be observed, the operation knob 32 is operated to start the bending angle amplification operation mode. Switch to direction control operation mode. As a result, when observing the observation target portion, when the bending portion 2b is bent to change the observation visual field, a fine operation becomes possible, and the observation visual field overruns the observation target portion. Therefore, the direction of the distal end of the insertion portion 2 can be controlled with high accuracy.

1 is an overall configuration diagram of a general endoscope. FIG. It is a structure explanatory view showing the structure of a mechanism that performs a bending operation of an endoscope. It is a principle figure of the ultrasonic motor for driving a pulley. It is sectional drawing of the bending operation means which shows one Embodiment of this invention. FIG. 6 is a configuration explanatory diagram of a biasing unit for returning the operation knob to a neutral position. It is structure explanatory drawing of a bending drive mechanism. It is composition explanatory drawing which shows the state which has inserted the endoscope of this invention in the large intestine. It is operation | movement explanatory drawing at the time of the swinging forward operation of an endoscope.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Main body operation part 2 Insertion part 2a Soft part 2b Bending part 2c Hard tip part 10 Bending drive means 11 Operation wire 12, 12UD, 12LR Pulley 14, 14UD, 14LR Ultrasonic motor 20 Bending operation means 21UD, 21LR Operation knob 22 Outer shaft 23 Inner shaft 24 Rotation angle detector 25UD, 25LR Encoder plate 26UD, 26LR Optical sensor 27a, 27b Spiral spring 30 Controller 31 Input / output ratio setting device 32 Operation knob

Claims (4)

In an endoscope bending portion drive device for connecting an insertion portion composed of a flexible portion, a bending portion, and a distal end hard portion to a main body operation portion, and bending the bending portion by remote operation from the main body operation portion,
A bending operation means provided in the main body operation unit and having a rotation operation member by manual operation and a rotation angle detection member for detecting a rotation angle of the rotation operation member;
At least a pair of operation wires connected to the distal end portion or the distal end hard portion of the bending portion, a pulley provided in the main body operation portion, and a base end side of each operation wire is wound around, and the pulley is rotated. A bending operation means having a rotational drive member for driving;
Control means for controlling to drive the rotation drive member of the bending operation means according to the rotation angle of the rotation operation member detected by the rotation angle detection member of the bending operation means;
An input / output ratio adjusting means for changing a ratio between a rotation angle detection signal from the bending operation means and a rotation angle of the pulley by the rotation driving member;
A direction control operation mode in which the bending portion is bent at an appropriate bending angle to turn the bending portion in an intended direction according to an operation by the rotation operation member, and the bending portion is swung. An internal view characterized by comprising a switching member that can be switched to a bending angle amplification operation mode for bending at a larger angle than when the rotation operation member is operated in the direction control operation mode. Mirror bending unit driving device.   2. The bending portion driving device for an endoscope according to claim 1, wherein at least one of the direction control operation mode and the bending angle amplification operation mode is configured to be capable of switching an input / output ratio in a plurality of stages.   2. The bending portion driving apparatus for an endoscope according to claim 1, wherein the bending angle amplification operation mode is configured such that an input / output ratio can be switched steplessly.   In order to bend the bending portion in the four directions of the up and down direction and the left and right direction, the operation wire is provided at four positions in the circumferential direction of the bending portion, and a pulley around which these operation wires are wound is provided. Two rotation operation members are provided for each pulley, and one pair of operation wires for bending the bending portion in the vertical direction and the other pair for bending operation in the left-right direction are provided. The operation wire is wound around a separate pulley, and the pulley whose input / output ratio can be changed by the input / output ratio adjusting means is a pulley that bends the bending portion in the vertical direction. The bending portion driving device for an endoscope according to claim 1.

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