JP2013183960A - Flexible endoscope with insertion shape detection function - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a flexible endoscope with a shape detection function which can perform accurate detection of an insertion part shape, is easy to assemble/disassemble, and has a conductive coil with no risk of breakage during a bending movement or the like of a bend part.SOLUTION: A coming-off prevention member 22 having a large diameter is fixed to a position near an distal end of a coil unit 20, the coming-off prevention member 22 is loosely inserted, in a freely axially movable manner, in an internal space of an intermediate part 30b of a coil unit distal end hold cylinder 30 attached to the distal end of a protection tube 21, a cylindrical plug body 31 fitted in a front side part 30c of the coil unit distal end hold cylinder 30 and a rear side part 30a of the coil unit distal end hold cylinder 30 function as a stopper of axial movement of the coming-off prevention member 22, and the coil unit distal end hold cylinder 30 and the distal end part of the protection tube 21 are fixed with their distal ends inserted in a coil assembly fixing hole 14a of an distal end part body 14 drilled from behind.

Description

  The present invention relates to a flexible endoscope having an insertion shape detection function.

  When a so-called flexible endoscope having a flexible insertion portion is used, an operator operating the endoscope grasps in real time how the insertion portion is bent in the body. It will be very easy to use.

  Therefore, detection obtained from an external coil device or the like disposed outside the body by inserting a plurality of conductive coils for generating a magnetic field or detecting a magnetic field in the inner region near the outer periphery of the insertion portion at an appropriate interval in the longitudinal direction. A system in which the bending state of the insertion portion is derived and displayed based on a signal value or the like has been put into practical use (for example, Patent Documents 1, 2, and 3).

  In a flexible endoscope having such an insertion shape detection function, a plurality of conductive coils arranged at appropriate intervals in the insertion portion are prevented from directly interfering with other various built-in objects or joint pieces of the bending portion. Each conductive coil is fixed to the inner peripheral portion of the protective tube and arranged in the insertion portion.

  Therefore, the protective tube has a function for restricting the arrangement of each conductive coil to a predetermined position and a protective function for protecting each conductive coil from direct interference with other built-in components. The distal end of the tube is fixed to the rear end portion of the distal end main body constituting the distal end of the insertion portion of the endoscope.

  Endoscope insertion parts (especially curved parts that bend with a small radius of curvature by remote control) are bent with an irregular radius of curvature when used for endoscopy, and correspondingly. An abnormal twisting force may act on the conductive coil.

  Then, in the inventions described in Patent Documents 1, 2, 3, etc., the conductive coil is disposed in the insertion portion in a state in which it cannot rotate in the direction around the axis along with the protective tube, so that an excessive twisting force is applied to the conductive coil. As a result, the conductive coil may be deteriorated or damaged, and accurate shape detection may not be possible.

  Therefore, the tip of the protection tube is engaged with the rear end of the tip body so as to be rotatable about the axis so that the protection tube to which the conductive coil is fixedly attached is rotatable about the axis. (For example, Patent Document 4).

  In such a case, when a large torsional force starts to act on the protective tube and the conductive coil, the protective tube rotates in the direction around the axis along with the conductive coil, thus preventing an excessive twisting force from acting on the conductive coil. it can.

JP 7-11968 JP-A-8-542 JP 2002-159437 A JP 2003-52611 A

  However, it cannot be said that the invention described in the cited document 4 is easy to assemble and disassemble, and is equivalent to the cross-sectional area of the protective tube in the vicinity of the rear end portion of the distal end body to which the distal end of the protective tube is fixed. Since a large dead space (that is, a space where other built-in objects cannot be arranged) is generated, even if an attempt is made to insert an additional built-in object such as a washing water injection tube, It can be difficult.

  In view of this, the inventor of the present invention has found that an irregular twisting force is applied to the conductive coil for detecting the bending state of the insertion portion even if the insertion portion is bent in an irregular direction with an irregular radius of curvature in endoscopy. Invented a flexible endoscope with an insertion shape detection function that can prevent the distal end portion of the protective tube surrounding the conductive coil from being placed in the insertion portion without causing a large dead space. (Patent application No. 2011-229511).

  However, in the invention, movement of the tip portion of the conductive coil in the axial direction is restricted. Therefore, when the bending part provided at the distal end of the insertion part of the endoscope is bent by remote operation and the built-in object moves greatly in the axial direction, the conductive coil does not apply excessive force in the axial direction. There was a risk of damage because it could not be moved.

  In the present invention, an abnormal torsional force hardly acts on the conductive coil for detecting the bending state of the insertion portion, accurate shape detection can be performed, and a large dead space is formed around the fixing portion at the tip of the protective tube. To provide a flexible endoscope having a durable shape detection function that is not possible and that is easy to assemble and disassemble, and that does not cause the conductive coil to be damaged when the bending portion is bent. With the goal.

  In order to achieve the above object, the flexible endoscope having the shape detection function of the present invention is flexible with a plurality of conductive coils for generating a magnetic field or for detecting a magnetic field spaced apart from each other in the longitudinal direction. In a flexible endoscope having an insertion shape detection function in which a coil unit configured integrally with a wire is disposed in a state of being surrounded by a common protective tube in a flexible insertion portion, A retaining member having an outer diameter larger than the outer diameter of the flexible wire and the conductive coil is fixed at a position near the tip, and a stepped cylindrical coil unit tip holding cylinder is provided at the tip of the protection tube. The inner space region of the coil unit tip holding cylinder is formed in a three-step stepped shape having a large inner diameter at the front portion and a smaller inner diameter at the rear portion. Inner diameter is The diameter is formed so that the conductive coil and the flexible wire pass and the retaining member does not pass, and the retaining member is loosely inserted in the inner space of the intermediate portion so as to be freely movable in the axial direction. A coil assembly fixing hole in which a tubular plug having a diameter through which a conductive coil and a flexible wire pass and a retaining member does not pass is fitted, and is drilled from the rear in the distal end main body constituting the most distal portion of the insertion portion Further, the coil unit tip holding cylinder and the tip portion of the protective tube are fixed in a inserted state.

  In addition, the outer peripheral surface of the coil unit tip holding cylinder is formed in a two-step stepped shape in which the inner diameter of the front part is large and the inner diameter of the rear part is small, and the front part is inserted into the coil assembly fixing hole, The coil unit tip holding cylinder is fixed to the coil assembly fixing hole with a fixing screw, and the protective tube coil assembly fixing hole may not be fixed directly.

  In addition, the outer peripheral surface of the coil unit tip holding cylinder is formed in a two-stepped shape with a large inner diameter of the front portion and a small inner diameter of the rear portion. The tip of the protective tube is fitted into the coil assembly fixing hole, the tip of the protective tube is adhesively fixed to the coil assembly fixing hole, and the coil unit tip holding cylinder and the coil assembly fixing hole are directly fixed. It does not have to be.

  And the rear side part of the outer peripheral surface of a coil unit front-end | tip holding cylinder may be fixed to there in the state inserted in the front-end | tip of a protection tube.

  According to the present invention, a retaining member having a large outer diameter is fixed to a position in the vicinity of the tip of the coil unit, and the retaining member is disposed in the inner space of the intermediate portion of the coil unit tip holding cylinder attached to the tip of the protective tube. A cylindrical plug body that is loosely inserted in the direction so as to be freely movable and fitted in the front part of the coil unit tip holding cylinder and the rear part of the coil unit tip holding cylinder serve as a stopper for axial movement of the retaining member, To detect the bending state of the insertion part by fixing the coil unit tip holding tube and the tip of the protective tube in the coil assembly fixing hole drilled in the tip part body from the rear. An abnormal torsional force is unlikely to act on the conductive coil, and accurate shape detection can be performed, and a large dead space can be created around the fixed part at the tip of the protective tube. , Moreover, it can be easily assembled and exploded, with excellent durability unlikely to cause damage conductive coil during bending operations of the bending portion.

1 is an overall configuration diagram of a flexible endoscope having a shape detection function according to a first embodiment of the present invention. It is side surface sectional drawing of the front-end | tip part of the insertion part of the flexible endoscope provided with the shape detection function which concerns on 1st Example of this invention. It is side surface sectional drawing which extracts and shows a part of front-end | tip part of the insertion part of the flexible endoscope provided with the shape detection function which concerns on 1st Example of this invention. FIG. 4 is a cross-sectional view taken along the line IV-IV in FIG. 2 of the flexible endoscope having the shape detection function according to the first embodiment of the present invention. It is side surface sectional drawing of the front-end | tip part of the insertion part of the flexible endoscope provided with the shape detection function which concerns on 2nd Example of this invention.

Hereinafter, a first embodiment of the present invention will be described with reference to the drawings.
FIG. 1 schematically shows the overall configuration of a flexible endoscope apparatus having an insertion shape detection function.
Reference numeral 10 denotes a flexible endoscope having an insertion shape detection function. The insertion part 12 connected to the lower end of the operation part 11 has a bending part 12a which can be bent at an arbitrary angle in an arbitrary direction by a remote operation from the operation part 11, and is covered with a soft flexible tube. It is connected to the tip of the flexible tube portion 12b. Reference numeral 15 denotes a bending operation knob for performing a bending operation of the bending portion 12a.

  The endoscope of this embodiment is a so-called forward-viewing type, and an observation window 13 and an illumination window are arranged on the distal end surface of the distal end main body 14 constituting the most distal portion of the insertion portion 12. However, a side view type or a perspective type may be used.

  In the insertion portion 12, a plurality of conductive coils 20 a for generating a magnetic field are arranged alongside the built-in components such as an imaging signal cable, an illumination light guide fiber bundle, a treatment instrument insertion channel, and various tubes. They are spaced apart from each other in the longitudinal direction.

  The imaging signal of the endoscope observation image output from the flexible endoscope 10 is sent to the video processor 1, and the endoscope observation image is displayed on the observation image display monitor 2. Further, an AC signal is applied from the control device 3 for detecting the insertion shape to the conductive coil 20a in the insertion portion 12 to generate a magnetic field, and the magnetic field detected by the external coil device 4 provided separately is supplied to the control device 3. Sent.

  In the control device 3, the bending shape of the insertion portion 12 is derived by calculation from a signal input from the external coil device 4, and the bending shape of the insertion portion 12 is displayed on the insertion portion shape display monitor 5 in real time. Note that the magnetic field generated by the external coil device 4 may be detected by the conductive coil 20a in the insertion portion 12. Since such a system for detecting an insertion shape is well known from Patent Documents 1 to 4 and the like, detailed description thereof is omitted.

  FIG. 2 shows the distal end portion of the insertion portion 12. The imaging signal of the endoscope observation image captured by the solid-state imaging device 16 through the observation window 13 disposed on the distal end surface of the distal end main body 14 is transmitted by the imaging signal cable 17 inserted and disposed in the insertion portion 12. .

  The conductive coil 20a is covered with a single insulating tube 20c (flexible wire) together with a conductive wire 20b extending in the longitudinal direction, and is long and flexible by the conductive coil 20a, the conductive wire 20b, and the insulating tube 20c. A flexible coil unit 20 is configured. The outer diameter size of the insulating tube 20c is substantially the same as the outer diameter size of the conductive coil 20a.

  Such a coil unit 20 is disposed at the axial position of a protective tube 21 made of an electrically insulating flexible tube such as a single fluororesin tube, and is surrounded by the protective tube 21 over its entire length. It is arrange | positioned in the insertion part 12.

  However, the coil unit 20 only needs to be arranged with a space from the inner peripheral surface of the protective tube 21, and does not necessarily have to be positioned at the axial position of the protective tube 21 except for the vicinity of the tip portion.

  The distal end body 14 has a round hole-shaped coil assembly fixing hole 14 a that is fixed in a state where the distal end portion of the protection tube 21 is fitted and inserted into the distal end body 14 so as to open to the rear end surface of the distal end body 14. It is formed straight in the direction parallel to the axis of the.

  Further, a marginal space hole 14b that fits in the vicinity of the foremost portion of the coil unit 20 with a sufficient gap as shown in the drawing is formed continuously at the front position of the coil assembly fixing hole 14a. .

  The marginal space hole 14b is not required to have a diameter sufficient for the protection tube 21 or a retaining member 22 to be described later, and the coil unit 20 only needs to be loosely accommodated, so that the inner diameter is smaller than the coil assembly fixing hole 14a. The boundary between the marginal space hole 14b and the coil assembly fixing hole 14a is stepped. And the front end surface of the coil unit front end holding | maintenance cylinder 30 mentioned later is applied to the wall surface which forms the step part.

  A coil assembly is constituted by the coil unit 20, the protective tube 21, the coil unit tip holding cylinder 30, the cylindrical plug 31 attached to the tip, and the like. FIG. 3 shows only such an assembly.

  For example, a short cylindrical retaining member 22 having an outer diameter larger than the outer diameter of the insulating tube 20c covered with the conductive coil 20a and the conductive wire 20b is fixed to a position near the tip of the coil unit 20. Yes.

  The retaining member 22 is formed of, for example, a stainless material or a hard plastic material. In this embodiment, the rear end portion of the conductive coil 20a in the forefront among the plurality of conductive coils 20a and the conductive wire 20b It is bonded and fixed to the outer peripheral surface of the insulating tube 20c at a position that spans. However, the fixed position does not necessarily have to be that position.

  A stepped cylindrical coil unit tip holding cylinder 30 is fixed to the tip of the protection tube 21 with the axis position aligned with the protection tube 21. The inner space region of the coil unit tip holding cylinder 30 is formed in a three-step stepped shape in which the inner diameter of the front portion is large and the inner diameter of the rear portion is small.

  Of these, the inner diameter of the rear portion 30a is formed such that the insulating tube 20c passes and the retaining member 22 cannot pass, and the retaining member 22 can move in the axial direction in the inner space of the intermediate portion 30b. Loosely interpolated.

  The cylindrical tube plug 31 made of a rigid body that is fitted in the front side portion 30c of the inner space of the coil unit tip holding cylinder 30 has a diameter that prevents the retaining member 22 from passing through the insulating tube 20c. A passage hole 31a is formed through the axial position.

  The outer peripheral surface of the coil unit tip holding cylinder 30 is formed in a two-stepped shape having a large inner diameter at the front portion and a smaller inner diameter at the rear portion. Then, the inner peripheral surface of the distal end of the protective tube 21 is bonded and fixed to the outer peripheral surface of the rear portion of the coil unit distal end holding cylinder 30, and the outer diameter of the outer peripheral surface of the distal end portion of the protective tube 21 and the coil exposed to the front side The outer diameter of the outer peripheral surface of the unit tip holding cylinder 30 is formed to have substantially the same dimension.

  Returning to FIG. 2, as described above, the distal end body 14 is provided with the coil assembly fixing hole 14 a straight from the rear end surface to the middle of the distal end body 14 toward the front, and the coil assembly fixing hole 14 a is formed therein. The unit tip holding cylinder 30 and the tip portion of the protection tube 21 are fitted and inserted from the rear (that is, inserted), and the coil unit tip holding cylinder 30 is inserted into the coil assembly fixing hole 14a of the tip body 14 with a fixing screw 33. It is fixed.

  The fixing screw 33 is screwed into a screw hole 34 formed in the tip end body 14. FIG. 4 is an IV-IV sectional view in which the portion is clearly shown, and the axis of the coil unit 20 when the bending portion 12a is operated by bringing the arrangement of the coil unit 20 as close as possible to the center position of the tip body 14. The direction moving length can be reduced.

  As shown in FIG. 2, the fixing screw 33 of this embodiment is a pointed tip screw having a sharp tip. A V-shaped circumferential groove with which the screw tip engages is formed over the entire outer periphery of the coil unit tip holding cylinder 30.

  During the assembly operation, the fixing screw 33 is tightened into the screw hole 34, whereby the coil unit tip holding cylinder 30 is firmly fixed to the coil assembly fixing hole 14a, and the attaching / detaching operation of the coil assembly with respect to the tip portion main body 14 is easily performed. be able to.

  In such a configuration, the protective tube 21 is not fixed directly to the coil assembly fixing hole 14a, but is stably fixed to the tip end body 14 via the coil unit tip holding cylinder 30. .

  In the present embodiment apparatus in which the coil assembly is configured as such, the coil unit 20 passes loosely through the rear portion 30a of the coil unit tip holding cylinder 30 and the coil passage hole 31a of the cylindrical plug body 31, The retaining member 22 fixed in the vicinity of the forefront of the coil unit 20 is disposed so as not to come out from the middle portion 30 b of the coil unit tip holding cylinder 30.

  However, the retaining member 22 is located in the middle portion 30b of the coil unit tip holding cylinder 30 at a position where it comes into contact with the rear end wall surface (front stopper surface 28) of the front cylindrical plug body 31 and the rear coil unit tip holding cylinder 30. It is possible to move freely in the axial direction between the position where the rear portion 30a hits the front side wall surface (rear stopper surface 29).

  Therefore, when a bending force is applied to the coil unit 20 by bending the bending portion 12a, the coil unit 20 can move freely in the axial direction with a margin. The bent shape of the insertion portion 12 can be accurately detected by the coil unit 20 without being damaged. When repairing or the like, if the fixing screw 33 is loosened, the coil assembly can be easily replaced, and no dead space is generated in the configuration.

  FIG. 5 shows a second embodiment of the present invention. Instead of using the fixing screw 33 as in the first embodiment as a means for fixing the protective tube 21 to the distal end body 14, the protection tube 21 is protected. The outer peripheral surface of the tube 21 is fixed to the inner peripheral surface of the coil assembly fixing hole 14a with an adhesive 40. Since other configurations are the same as those of the first embodiment, description thereof is omitted.

  It should be noted that the coil unit tip holding cylinder 30 is not fixed directly to the coil assembly fixing hole 14a by applying only to the protective tube 21 without applying an adhesive, so that repair and replacement are easy. Become.

  With this configuration, since the fixing screw 33 is unnecessary, the dead space in the configuration can be further reduced as compared with the first embodiment. For example, an additional built-in device such as a washing water injection pipe There is an advantage that a hole for passing an object can be easily drilled and provided in the tip end body 14.

  In addition, this invention is not limited to the said Example, The said other various embodiment can be included.

DESCRIPTION OF SYMBOLS 10 Flexible endoscope 12 Insertion part 12a Bending part 14 Tip part main body 14a Coil assembly fixing hole 20 Coil unit 20a Conductive coil 20b Conductive wire 20c Insulating tube 21 Protection tube 30 Coil unit tip holding cylinder 30a Rear part 30b Middle part 30c Front side Portion 31 Tubular plug 31a Coil passage hole 40 Adhesive

Claims (4)

A coil unit formed by assembling a plurality of conductive coils for generating a magnetic field or detecting a magnetic field integrally with a flexible wire with a space therebetween in the longitudinal direction provides a common protection in the flexible insertion portion. In a flexible endoscope with an insertion shape detection function arranged in a state surrounded by a tube,
A retaining member having an outer diameter larger than the outer diameter of the flexible wire and the conductive coil is fixed to a position near the tip of the coil unit,
At the tip of the protective tube, a stepped cylindrical coil unit tip holding cylinder is fixed in alignment with the protective tube and the axial position,
The inner space region of the coil unit front end holding cylinder is formed in a three-stage stepped shape in which the inner diameter of the front part is large and the inner diameter of the rear part is small, and the inner diameter of the rear part is the same as that of the conductive coil. The flexible wire is formed to have a diameter through which the retaining member does not pass, and the retaining member is loosely inserted in the inner space of the intermediate portion so as to be freely movable in the axial direction. A cylindrical plug having a diameter through which the conductive coil and the flexible wire pass and the retaining member does not pass is fitted,
The coil unit front end holding tube and the front end portion of the protective tube are fixed in a state where they are inserted into a coil assembly fixing hole formed in the front end portion body constituting the most distal portion of the insertion portion from the rear. Flexible endoscope with insertion shape detection function   The outer peripheral surface of the coil unit tip holding cylinder is formed in a two-step stepped shape in which the inner diameter of the front portion is large and the inner diameter of the rear portion is small, and the front portion is inserted into the coil assembly fixing hole, The flexible endoscope having a shape detection function according to claim 1, wherein the coil unit tip holding cylinder is fixed to the coil assembly fixing hole with a fixing screw.   The outer peripheral surface of the coil unit tip holding cylinder is formed in a two-stepped shape with a large inner diameter of the front portion and a small inner diameter of the rear portion, and the front portion of the outer peripheral surface of the coil unit tip holding tube is The flexible inner part having a shape detection function according to claim 1, wherein a distal end portion of the protection tube is fitted into the coil assembly fixing hole, and a distal end portion of the protection tube is adhesively fixed to the coil assembly fixing hole. Endoscope.   The flexible endoscope having a shape detection function according to claim 2 or 3, wherein a rear side portion of the outer peripheral surface of the coil unit tip holding cylinder is fixed to the tip portion of the protective tube in a state of being inserted into the tip of the protection tube.

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