JP5481280B2 - Endoscope shape detection probe - Google Patents

Description

  The present invention relates to a shape detection probe for an insertion portion of an endoscope.

  2. Description of the Related Art In general, endoscopes that can observe and image a target region by inserting a long and thin insertion portion into a body cavity of a patient are widely used. Especially in colonoscopy and small intestine endoscopy, grasp the position of the insertion part in the body cavity so that the operation part can be advanced without damaging the intestinal tract that is flexible and tortuously curved A shape detecting device is used.

  Patent Document 1 proposes such a shape detection device. In Patent Document 1, a shape detection probe in which coils that generate a magnetic field are arranged along a core line at a predetermined interval is provided in the insertion portion of an endoscope along the longitudinal direction of the insertion portion. A signal line is connected to each coil in the shape detection probe. The signal line extends from each coil to the proximal end of the endoscope, and the core wire is wound spirally. When the endoscope and the video processor are connected, the signal line is electrically connected to the signal line on the video processor side.

  In Patent Document 1, a current is passed through each coil of the shape detection probe via a signal line to generate a magnetic field in each coil. The output of the magnetic field generated in each coil is detected by a magnetic field detection device outside the body. Based on the detected magnetic field output of each coil, the position of each coil and the relative arrangement of each coil are specified. Furthermore, the shape of the entire insertion portion of the endoscope is detected by obtaining the curvature of the insertion portion of the endoscope at the position where each coil is provided.

  Alternatively, the magnetic field generated by the external magnetic field generator can be detected by each coil. In this case, when the insertion portion of the endoscope moves in the body cavity, an induced electromotive force is generated in each coil due to a change in magnetic flux passing through each coil, and a current is applied to the signal line connected to each coil. Flows. Then, by detecting the current generated in each coil, the position of each coil and the relative arrangement of each coil are specified. Therefore, as in the case where a current is passed through each coil, the shape of the entire insertion portion of the endoscope can be detected by obtaining the curvature of the insertion portion of the endoscope at the position where each coil is provided. it can.

  In the shape detection probe disclosed in Patent Document 1, a coil, a signal wire, and a core wire are covered with a flexible tubular tube. And a tube has the 1st coating | coated part which adhere | attaches and coat | covers on the coil outer periphery, and the 2nd coating | coated part which coat | covers a core wire and a signal wire | line. The outer diameter of the second covering portion is smaller than that of the first covering portion. The first covering portion and the second covering portion are alternately arranged to constitute a tube.

Japanese Patent No. 3791664

  When inserting the insertion portion of the endoscope into a tubular digestive organ having a large number of bent portions such as the large intestine and the small intestine, the flexible tube of the insertion portion is meandered by combining various bending operations. For this reason, built-in objects such as various wirings arranged in the insertion portion and fibers for guiding illumination light are twisted in an arbitrary direction or sandwiched between other built-in objects by a bending operation. Since the neutral axis of each built-in object is different, each built-in object is pulled or compressed when the insertion portion is curved. Therefore, if there are irregularities in the longitudinal direction as in the conventional shape detection probe, for example, when it is pulled while being sandwiched between other built-in objects, the coil in the probe is caught by other built-in objects become. For this reason, the load is concentrated on the coil, which may cause damage to the probe and other built-in objects sandwiching the coil.

  The present invention has been made in view of the above circumstances. An object of the present invention is to provide a highly durable shape detection probe without being caught by other built-in objects even when the endoscope repeats bending in an arbitrary direction.

A shape detection probe according to an embodiment of the present invention includes a plurality of coils provided at predetermined intervals along the longitudinal direction of the shape detection probe, and a signal line extending from each coil to the proximal end side of the shape detection probe. And a first exterior member that covers the entire circumference of the shape detection section, the first exterior member being a flexible tube, and a distal end member fitted into the distal end of the tube; The inner diameter of the tube is larger than the outermost diameter of the shape detector, and the tip of the shape detector is fixed to the tip member, and a predetermined gap is formed between the outer periphery of the shape detector and the inner periphery of the tube . It is supported to have a clearance.

Preferably, a flexible second exterior member that covers the entire circumference of the shape detection unit is provided between the tube and the shape detection unit, and the outer periphery of the second exterior member and the inner periphery of the tube There is a predetermined clearance between them. Thereby, durability of a shape detection tube can be improved by the anti-bending effect which a 2nd exterior member brings about, without making the movement of the coil according to the curvature of an endoscope obstruct | occluded by another built-in thing. .

  More preferably, a reinforcing member that increases the rigidity of the first exterior member is provided on the outer peripheral surface of the first exterior member corresponding to the curved portion of the endoscope. Thereby, the buckling prevention effect of the shape detection tube when the endoscope is bent can be expected.

  According to the shape detection probe of the present invention, the durability of the probe itself can be improved while preventing the movement of the coil in the shape detection probe from being obstructed even when pulled or compressed by other built-in objects in the endoscope. Can be improved.

FIG. 1 is a schematic diagram illustrating an endoscope system including a shape detection probe according to an embodiment of the present invention. FIG. 2A is a perspective view showing an outline of the shape detection probe according to the first embodiment of the present invention, and FIG. 2B is a front end portion of the shape detection probe according to the first embodiment of the present invention. FIG. FIG. 3 is a schematic cross-sectional view of the shape detection probe in the first embodiment of the present invention. FIG. 4 is a partial cross-sectional view of the operation unit of the endoscope according to the first embodiment of the present invention. FIG. 5 is a schematic cross-sectional view of a shape detection probe according to the second embodiment of the present invention. FIG. 6 is a schematic cross-sectional view of a shape detection probe according to the third embodiment of the present invention.

  Hereinafter, a shape detection probe according to an embodiment of the present invention will be described with reference to the drawings. In addition, the same number is attached | subjected, when showing the same member over several figures. In the endoscope, the distal end side is the distal end side, and the base side is the proximal end side.

  FIG. 1 shows a schematic diagram of an endoscope system 100 including a shape detection probe according to an embodiment of the present invention. The endoscope system 100 includes an endoscope 1, a video processor 2, a controller 3, a monitor 4, a system cart 5, and a generator 6. The endoscope 1 has an insertion portion 7 including a distal end portion 8, a bending portion 9, and a flexible tube 29. The bending portion 9 is configured to be bendable by an angle knob 11 that is rotatably provided on an operation portion 10 connected to the proximal end of the insertion portion 7. The bending mechanism of the bending portion 9 is a mechanism incorporated in a general endoscope, and the bending portion 9 is bent by pulling the operation wire in conjunction with the turning operation of the angle knob 11. Furthermore, a distal end portion 8 is provided at the distal end of the curved portion 9 and is covered with a resin having a hard property. The imaging region of the endoscope 1 is changed by changing the direction of the distal end portion 8 according to the bending operation by the operation of the operation unit 10. The operation unit 10 is connected to the video processor 2 via a universal cable 12 and a base unit 13. The base 13 is connected to the controller 3 via the cable 14. Furthermore, the video processor 2 is connected to a monitor 4.

  The system cart 5 is provided with a movable arm 15. A generator 6 is attached to the tip of the arm 15. The generator 6 is connected to the controller 3 by a cable 16. The controller 3 has a high frequency power supply circuit and supplies a high frequency current to the generator 6 through the cable 16. The generator 6 generates a magnetic field by the supplied high frequency current. The magnetic field generated from the generator 6 is detected by each coil 40 of the shape detection probe 39 in the endoscope 1. When the magnetic flux penetrating each coil changes according to the bending operation of the endoscope 1, an induced electromotive force is generated in each coil, and a current flows through a signal line connected to each coil. The current generated in each coil is sent to the signal processing circuit of the controller 3. The signal processing circuit identifies the position of each coil and the relative arrangement of each coil by detecting the current generated in each coil. And the shape of the endoscope 1 can be detected by calculating | requiring the curvature of the endoscope in the position in which each coil is provided. Details of the shape detection probe 39 will be described later.

  2A and 2B are diagrams showing a schematic configuration of the insertion portion 7 of the endoscope 1. In the bending portion 9, a plurality of bending pieces 20 that are metal ring members are connected to bend in the longitudinal direction. A metal blade 21 formed by knitting a metal ultrafine thread is covered over the entire outer peripheral surface of the bending piece 20. Further, a long hollow cylindrical covering member 22 made of an insulating resin material having biocompatibility is covered over the entire circumference of the metal blade 21. The insertion portion 7 has a flexible tube 29 made of an insulating member. Inside the flexible tube 29, a built-in object of the endoscope 1 is inserted.

  FIG. 2B is an enlarged front view of the distal end portion 8 of the endoscope 1. An objective optical system 23, illumination optical systems 24 and 25, a water supply nozzle 26, an air supply nozzle 27, and a forceps port 28 are provided on the front surface of the distal end portion 8. The illumination optical systems 24 and 25 advance the illumination light propagated to the distal end portion 8 to the observation target site. The objective optical system 23 advances reflected light of illumination light from the observation target site to the light receiving surface of the image sensor. The water supply nozzle 26 and the air supply nozzle 27 expand the patient's lumen by air supply to secure a visual field, or when the observation performance of the electronic endoscope is deteriorated due to contamination of the objective lens surface due to body fluid or bleeding, It is used when water is sprayed to remove dirt on the lens surface, and the field of view is restored by sending air and flying water droplets on the surface of the objective lens, or when air is sprayed on the surface of the object to clean it. The surgeon operates the water supply button or the air supply button of the operation unit 10 to send a desired fluid or gas to the water supply nozzle 26 or the air supply nozzle 27 through the water supply channel 36 or the air supply channel 37, respectively. The forceps port 28 is used when performing a biopsy or treatment using a treatment tool, or sucking out body fluid, blood, water jetted from the water supply nozzle 26, or the like. The operator inserts the treatment tool from the forceps insertion port of the operation unit 10 and causes the treatment tool to appear and disappear from the forceps port 28 via the forceps channel 38. Although not actually appearing in front of the tip 8, the position of the shape detection probe 39 when viewed from the front of the tip 8 is indicated by a dotted circle. As shown in the figure, the shape detection probe 39 is provided at a position eccentric from the center O of the cross section perpendicular to the longitudinal direction in the insertion portion 7 of the endoscope 1.

  The light source unit of the video processor 2 includes a high-intensity lamp such as a xenon lamp, a halogen lamp, a mercury lamp, or a metal halide lamp, and generates white light as illumination light. The light source unit includes a condenser lens that collects light from the light source, a color filter for sequentially separating the white light from the light source into red (R), green (G), and blue (B) light, and an image. A color filter rotation control circuit for controlling the speed and phase of the color filter so that the color filter rotates in synchronization with a timing pulse or a vertical synchronization signal when writing a signal to the frame memory, for adjusting the amount of illumination light Light quantity diaphragm, a circuit for controlling the light quantity diaphragm, and the like, and generates illumination light by a frame sequential method. Note that the imaging method may be a simultaneous imaging method instead of the frame sequential method. That is, the white light of the light source is condensed and propagated to the light guide as it is, irradiated to the observation target part, the complementary color signal is separated by an on-chip complementary color filter on the image sensor, and this complementary color signal is converted into R, G , B can be converted into a primary color signal, and this primary color signal can be obtained by a color difference matrix.

  In the endoscope 1, optical fibers 34 and 35 are inserted from the base portion 13 into the universal cable 12, the operation portion 10, and the insertion portion 7, and extend to the distal end portion 8. Therefore, the illumination light emitted from the light source unit is propagated through the endoscope 1 via the base unit 13 by the optical fibers 34 and 35. The illumination light propagated to the distal end portion 8 is emitted from the illumination optical systems 24 and 25 and proceeds to the target site. The return light reflected by the target part travels to the light receiving surface of the image sensor by the objective optical system 23 and forms an image of the target part. The light received by the image sensor is photoelectrically converted into an image signal, and then sent to the image signal processing circuit of the video processor 2 via the base 13 by the image sensor cable 33.

  The image signal processing circuit of the video processor 2 performs various signal processing such as clamping, knee, γ correction, and interpolation processing on the input signal, converts the processed signal into a digital signal sequence, and stores it in an image memory. Output. The image memory buffers the input image signal in units of frames. The video signal processing circuit sends the image signal swept from the image memory at a predetermined timing to the video signal output circuit. The video signal output circuit converts the image signal into a video signal conforming to a predetermined standard such as NTSC (National Television System Committee) or PAL (Phase Alternating Line) and outputs the video signal to the monitor 4. Thereby, a color image of the target part is displayed on the monitor 4.

  FIG. 3 is a cross-sectional view schematically showing the shape detection probe 39 according to the first embodiment of the present invention. A plurality of coils 40 are provided in the shape detection probe 39 along the longitudinal direction of the shape detection probe 39 at predetermined intervals. The coil 40 includes a winding 40a in which a wire such as a copper wire is spirally wound, and a long hollow cylindrical protective tube 40b that covers the winding 40a. From each coil 40, a signal wire 41 of a coated thin wire extends. The signal line 41 extends from each coil 40 to the base 13. Therefore, in the insertion part 7, the number of the signal lines 41 between the coils increases toward the proximal end side. In addition, since the distance between each coil 40 is maintained by the signal line 41, the distance between the coils is maintained without being close. The distal end coil 40 is fitted and fixed in a recess formed on the proximal end side of the distal end member 43 of the shape detection probe 39. The tip member 43 includes a tip-side large-diameter portion 43a and a small-diameter portion 43b having a smaller diameter than the outer diameter of the large-diameter portion 43a. The small diameter portion 43b is fitted in a tube 44 having a substantially uniform outer diameter. The tube 44 is preferably formed of a resin having a small friction coefficient, excellent durability, and flexibility, such as PTFE (Polytetrafluoroethylene). The tip member 43 and the tube 44 constitute an exterior member 46 in the shape detection probe 39.

  As shown in FIG. 3, each coil 40 and the signal line 41 constitute a shape detection unit 45, and the shape detection unit 45 is covered with the tube 44 of the exterior member 46 over the entire circumference. The outer diameter of the exterior member 46 is larger than the outermost diameter of the shape detection unit 45. That is, a clearance is provided between the shape detection unit 45 and the tube 44. Therefore, when the insertion portion 7 of the endoscope 1 is repeatedly bent in an arbitrary direction, the tube 44 protects each coil so that it can freely advance and retract even if the shape detection probe 39 is sandwiched between other built-in objects. For this reason, even if the shape detection probe 39 is pulled or compressed by another built-in object, the other built-in object is not caught by the large-diameter portion where the coil 40 is provided as in the prior art. That is, the shape detection probe 39 can move in the longitudinal direction of the insertion portion 7 of the endoscope 1 according to pulling or compression.

  FIG. 4 is a partial cross-sectional view illustrating an outline of the operation unit 10 of the endoscope 1. In the sectional view, only members necessary for explanation are shown. The shape detection probe 39 is connected to the base body 50 in the operation unit 10. The base body 50 is fixed to a metal frame 51 of the operation unit 10. The proximal end of the tube 44 of the shape detection probe 39 is fitted with the distal end of the base body 50. Since it is not necessary to provide a coil on the base end side of the base body 50, only the signal line 41 extends from the base end of the base body 50. The signal line 41 extends from the operation unit 10 to the base unit 13 through the universal cable 12. The signal line 41 is electrically connected to the video processor 2.

  FIG. 5 is a cross-sectional view showing an outline of a shape detection probe 69 in the second embodiment of the present invention. Since members other than those shown in FIG. 5 are the same as those in the first embodiment, illustration and description thereof are omitted. In the shape detection probe 69, a plurality of coils 60 are provided along the longitudinal direction of the shape detection probe 69 at predetermined intervals. As in the first embodiment, the coil 60 includes a winding 60a and a protective tube 60b that covers the winding 60a. From each coil 60, a signal wire 61 of a coated thin wire extends and extends to the proximal end side of the endoscope 1. The signal line 61 extends from each coil 60 to the base 13.

  As shown in FIG. 5, each coil 60 and the signal line 61 constitute a shape detection unit 66 as in the first embodiment. Further, the tip member 63 and the tube 64 constitute an exterior member 67. The distal end coil 60 is fitted and fixed in a recess formed on the proximal end side of the distal end member 63 of the shape detection probe 69. The tip member 63 includes a tip-side large-diameter portion 63a and a small-diameter portion 63b having a smaller diameter than the outer diameter of the large-diameter portion 63a. The small diameter portion 63b is fitted into a tube 64 having a substantially uniform outer diameter. The tube 64 is formed of a resin having a small friction coefficient, excellent durability, and flexibility, such as PTFE.

  As shown in FIG. 5, in this embodiment, another tube 65 is provided in the longitudinal direction of the shape detection probe 69 on the inner peripheral side of the tube 64. The tube 65 is formed by covering the coil 60 and the signal line 61 using a heat-shrink rubber tube, a silicon rubber tube, or the like. Further, the tube 65 as another exterior member has a first covering portion 65 a that covers the outer periphery of the coil 60 in close contact with it, and a second covering portion 65 b that covers the signal line 61. The outer diameter of the second covering portion 65b is smaller than that of the first covering portion 65a. The first covering portion 65a and the second covering portion 65b are alternately arranged to constitute the tube 65. The distal end portion of the tube 65 is applied to the distal end member 63 so as to cover the outer periphery of the distal end coil 60. By providing the tube 65, the inter-coil distance of each coil 60 can be more stably maintained as compared with the first embodiment.

  A clearance is provided between the tube 64 and the tube 65. Therefore, similarly to the first embodiment, even when the shape detection probe 69 is sandwiched between other built-in objects, the tube 64 protects the tube 65 so as to freely advance and retract. For this reason, even if the shape detection probe 69 is pulled or compressed by another built-in object, the other built-in object is not caught by the large-diameter portion where the coil 60 is provided as in the prior art. Therefore, the shape detection probe 69 can move in the longitudinal direction of the insertion portion 7 of the endoscope 1 according to pulling or compression. Further, since the coil 60 and the signal line 61 are protected by the tubes 64 and 65, it is possible to expect an improvement in durability due to the bending prevention effect of the shape detection probe 69.

  FIG. 6 is a cross-sectional view schematically showing a shape detection probe 79 according to the third embodiment of the present invention. Since members other than those shown in FIG. 6 are the same as those in the first embodiment, illustration and description thereof are omitted. As shown in the figure, each coil 70 and the signal line 71 constitute a shape detector 72 as in the first embodiment. As in the first embodiment, the coil 70 includes a winding 70a and a protective tube 70b covering the winding 70a. Further, the tip member 73 and the tube 74 constitute an exterior member 75. In the present embodiment, a spiral groove 76 is formed on the outer peripheral surface of the tube 74 along the longitudinal direction at the distal end portion of the tube 74 constituting the outer frame of the shape detection probe 79. A coil spring (reinforcing member) 77 made of a thin metal wire is fitted in the spiral groove 76. Further, an adhesive 78 is applied to the groove 76 so as to cover the coil spring 77. The coil spring 77 is provided so as to be expandable and contractable in the longitudinal direction of the tube 74, and increases the rigidity of the tube 74. The other components of the shape detection probe 79 not described here are the same as those in the second embodiment. Therefore, in this embodiment, not only the durability of the shape detection probe 79 is improved as in the second embodiment, but also the shape detection probe when sandwiched between other built-in objects in the endoscope 1. 79 buckling can be more effectively prevented. Since bending frequently occurs in the bending portion 9 of the endoscope 1, the spiral groove 76, the coil spring 77, and the adhesive 78 are formed in a range extending over the bending portion 9 of the endoscope 1. Is preferred.

  This completes the description of the embodiment of the present invention. The present invention is not limited to the above-described configuration, and various modifications can be made within the scope of the technical idea of the present invention. In the above description, the magnetic field generated from the generator is detected by the coil of the shape detection probe. However, the position of each coil can also be specified by detecting the magnetic field generated by passing a current through each coil of the shape detection probe by the magnetic field detection means outside the body. In this case, if the generator is replaced with a magnetic field detection means and the controller is replaced with a magnetic field detection device, the shape of the endoscope inserted into the body cavity of the patient can be detected without changing the configuration of the shape detection probe. .

  In the second and third embodiments, the tube covering the coil and the signal line is provided with the first covering portion and the second covering portion. However, these covering portions are not provided, but a long cylindrical shape is provided. Even if the tube is employed, the shape detection tube can be prevented from being folded. Furthermore, it is good also as a structure which provides the coil spring in 3rd Embodiment in the tube of 1st Embodiment. Further, even if a metal blade formed by knitting a thin metal wire at the tip of the tube 74 instead of the groove and coil spring of the third embodiment is bonded or embedded as a reinforcing member, the same anti-bending effect is obtained. It is done. And in said description, although the shape detection part is comprised with the coil and the signal wire | line, it uses the thin core wire which consists of a fiber which has durability and flexibility, such as nylon (trademark) and an aramid, further. Each coil may be fixed to the core wire with an adhesive or the like.

DESCRIPTION OF SYMBOLS 1 Endoscope 7 Insertion part 9 Bending part 39,69,79 Shape detection probe 40,60,70 Coil 41,61,71 Signal line 44,64,65,74 Tube 45,66,73 Shape detection part 46,67 , 75 Exterior member 77 Coil spring (reinforcing member)

Claims (3)

In the endoscope shape detection probe,
A shape detection unit having a plurality of coils provided at predetermined intervals along the longitudinal direction of the shape detection probe, and a signal line extending from each coil to the proximal end side of the shape detection probe;
A first exterior member that covers the entire shape detection unit,
The first exterior member includes a flexible tube, and a tip member fitted into the tip of the tube,
The inner diameter of the tube is larger than the outermost diameter of the shape detection unit,
The shape detection unit is supported such that a tip thereof is fixed to the tip member and has a predetermined clearance between an outer periphery of the shape detection unit and an inner periphery of the tube .
An endoscope shape detection probe characterized by that. Between the tube and the shape detection unit, a flexible second exterior member that covers the entire shape detection unit is provided,
Having a predetermined clearance between the outer periphery of the second exterior member and the inner periphery of the tube ;
The endoscope shape detection probe according to claim 1. The outer peripheral surface corresponding to the curved portion of the endoscope of the first exterior member, according to claim 1 or claim reinforcing member to increase the rigidity of the first outer member is provided, it is characterized by The endoscope shape detection probe according to 2.

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