WO2018105165A1

WO2018105165A1 - Oct catheter

Info

Publication number: WO2018105165A1
Application number: PCT/JP2017/026534
Authority: WO
Inventors: 大佐々木; 芳享為國; 卓朗渡邊; 貴広菊地
Original assignee: 住友電気工業株式会社
Priority date: 2016-12-05
Filing date: 2017-07-21
Publication date: 2018-06-14

Abstract

This OCT catheter is provided with: an interior body comprising an optical fiber that transmits light and extends in the direction of transmission as a longitudinal direction; an exterior body comprising a first exterior body for covering the longitudinal distal end of the interior body, a second exterior body for covering the longitudinal proximal end of the interior body, and a tube that is connected to the first exterior body and the second exterior body and covers the interior body; a first alignment part for setting the positions in the longitudinal direction of the interior body and the first exterior body to a first reference position; and a second alignment part for setting the positions in the longitudinal direction of the interior body and the second exterior body to a second reference position. The length of the interior body between the first reference position and the second reference position is longer than the length of the exterior body between the first reference position and the second reference position.

Description

OCT catheter

The present disclosure relates to an OCT catheter. This application claims priority based on Japanese Patent Application No. 2016-235868 filed on Dec. 5, 2016, and incorporates all the content described in the Japanese application.

Patent Document 1 discloses an OCT (Optical Coherence Tomography) catheter for acquiring a cross-sectional image in a living body. A catheter disclosed in Patent Document 1 includes a hollow torque coil that is rotated by a drive unit, an optical fiber that is disposed in a hollow portion of the torque coil and rotates together with the torque coil, a protective tube that covers the torque coil, and a protective tube. A probe connected to the tip and a handle for operating the probe are provided.

JP 2013-141499 A

An OCT catheter according to an embodiment of the present disclosure includes an inner body including an optical fiber that transmits light and extends in the transmission direction as a longitudinal direction, a first outer body that covers a longitudinal tip of the inner body, and the inner body. The exterior body including the second exterior body that covers the base end in the longitudinal direction, and the tube that is connected to the first exterior body and the second exterior body and covers the interior body, and the longitudinal length of the interior body and the first exterior body A first positioning part that regulates the mutual position in the direction at the first reference position, and a second positioning part that regulates the mutual position in the longitudinal direction of the interior body and the second exterior body at the second reference position. The length of the interior body from the first reference position to the second reference position is longer than the length of the exterior body from the first reference position to the second reference position.

FIG. 1 is a diagram illustrating a configuration of an OCT apparatus according to an embodiment. FIG. 2 is a cross-sectional view showing the handpiece side of the OCT catheter. FIG. 3 is an exploded perspective view showing the connector structure of the OCT catheter. FIG. 4 is a cross-sectional view showing the connector structure of the OCT catheter. FIG. 5A is a perspective view illustrating a connector structure of an OCT catheter. FIG. 5B is a perspective view illustrating the connector structure of the OCT catheter. FIG. 6A is a diagram for explaining the connecting operation of the OCT catheter. FIG. 6B is a diagram for explaining the connecting operation of the OCT catheter. FIG. 7A is a schematic diagram showing the relationship between the length of the exterior body and the interior body of the OCT catheter. FIG. 7B is a schematic diagram showing the relationship between the length of the exterior body and the interior body of the OCT catheter.

[Problems to be solved by the present disclosure]
In general, in an OCT catheter inserted into a blood vessel, a predetermined range of light in the longitudinal direction of the exterior body is obtained by moving the position of the light emitting portion rearward relative to the exterior body such as a protective tube (pullback). Obtain an optical coherence tomography image. Therefore, in such an OCT catheter, the light emitting portion is movable in the longitudinal direction of the exterior body. On the other hand, for example, when an optical coherence tomographic image at a predetermined position is acquired as in fundus observation, it is necessary to perform control so that the light emitting unit stops at the predetermined position. However, when the position of the light emitting unit is controlled, it is difficult to stably acquire the optical coherence tomographic image.

[Effects of the present disclosure]
According to the OCT catheter according to the present disclosure, an optical coherence tomographic image can be stably acquired.

[Description of Embodiment of Present Invention]
First, the contents of the embodiments of the present invention will be listed and described. An OCT catheter according to an embodiment of the present invention includes an inner body including an optical fiber that transmits light and extends in the transmission direction as a longitudinal direction, a first outer body that covers a distal end in the longitudinal direction of the inner body, and the inner body. The exterior body including the second exterior body that covers the base end in the longitudinal direction, and the tube that is connected to the first exterior body and the second exterior body and covers the interior body, and the longitudinal length of the interior body and the first exterior body A first positioning part that regulates the mutual position in the direction at the first reference position, and a second positioning part that regulates the mutual position in the longitudinal direction of the interior body and the second exterior body at the second reference position. The length of the interior body from the first reference position to the second reference position is longer than the length of the exterior body from the first reference position to the second reference position.

When the position of the light emitting portion is controlled as in the prior art, for example, when an exterior body such as a protective tube is extended by an external force, the optical fiber may also be extended by the external force. In order to obtain an optical coherence tomographic image, it is necessary to keep the optical path length constant. However, such an extension of the optical fiber causes fluctuations in the optical path length, which may make it difficult to perform stable measurement. .

In the OCT catheter according to one embodiment, the relative position in the longitudinal direction between the interior body and the exterior body is controlled by the first positioning portion and the second positioning portion so as not to shift. Therefore, even when an optical coherence tomographic image at a predetermined position is acquired, the optical fiber is prevented from shifting in the longitudinal direction. In the range from the first reference position to the second reference position, the length of the interior body is longer than the length of the exterior body. Thereby, the interior body including the optical fiber can be arranged in a slack state in the internal space of the exterior body. Therefore, even if the exterior body such as a tube is extended by an external force or the like, the external force applied to the exterior body is not easily transmitted to the interior body. Therefore, fluctuations in the optical path length hardly occur, and an optical coherence tomographic image can be acquired stably.

Further, in one embodiment, the inner body may have a torque wire that transmits rotation from the proximal end in the longitudinal direction to the distal end, and the optical fiber may be included in a hollow portion of the torque wire. In this case, the optical fiber can be rotated by rotating the torque wire.

In one embodiment, the length of the interior body from the first reference position to the second reference position may be 0.1 to 1% longer than the length of the exterior body from the first reference position to the second reference position. Good. When the length of the interior body is 0.1% or more longer than the length of the exterior body, an external force applied to the exterior body is difficult to be transmitted to the interior body. Moreover, since an interior body is not too long, it is suppressed that the inner side of an exterior body and an interior body interfere more than necessary.

[Details of the embodiment of the present invention]
Embodiments according to the present invention will be specifically described below with reference to the drawings. In addition, this invention is not limited to these illustrations, is shown by the claim, and intends that all the changes within the meaning and range equivalent to a claim are included. For convenience, the same reference numerals are given to substantially the same elements, and the description thereof may be omitted. In the following description, the axial direction (longitudinal direction) of the OCT catheter is expressed as the front-rear direction, the proximal end side is the rear side, and the distal end side is the front side. Further, in the case of the radial direction, the circumferential direction, and the rotation, unless otherwise specified, the axis center of the OCT catheter is used as a reference.

FIG. 1 is a diagram showing a configuration of a medical imaging system 1 for acquiring an optical coherence tomographic image. As shown in FIG. 1, the medical imaging system 1 includes a console body 2, a rotation drive device 7, and an OCT catheter 10.

The console body 2 includes a light source that realizes a basic function for acquiring an in-vivo image, an optical measurement unit, a control unit, a computer that performs image calculation, and a power source. A caster 2a is attached to the console body 2 so that an operator can easily move the console body 2. In addition, a drive 3 into which a recording medium is inserted, a monitor 5 for displaying an imaging image, and an input means 6 such as a keyboard and a mouse for operation input are provided on the console body 2.

The rotational drive device 7 is a device that performs a rotational scanning operation in the OCT catheter 10. The rotary drive device 7 is connected to the console body 2 via a cable 8 including electrical wiring and an optical fiber. The rotary drive device 7 is arranged near the patient away from the console body 2. The rotation drive device 7 is provided with a connection port 7a to which the connector shell 220 on the proximal end side of the OCT catheter 10 is connected. An alignment portion 7b for aligning the connector shell 220 in the circumferential direction of the OCT catheter 10 is provided at the periphery of the connection port 7a. The alignment portion 7b in the illustrated example is a rectangular cutout formed at one location on the periphery of the connection port 7a. Further, a handpiece 230 that is grasped by a user when an optical coherence tomographic image is acquired is provided on the distal end side of the OCT catheter 10. Hereinafter, the OCT catheter 10 will be described in detail.

First, the front end side of the OCT catheter 10 will be described. FIG. 2 is a cross-sectional view showing the handpiece side of the OCT catheter. As shown in FIG. 2, the OCT catheter 10 includes an inner body 100 including a torque wire 121 and an optical fiber 125, and an outer body 200 that covers the inner body 100. The optical fiber 125 is a general single mode optical fiber. The optical fiber 125 has a structure in which a glass fiber including a high refractive index core and a low refractive index clad is covered with a resin coating. The base end of the optical fiber 125 is fixed to the optical connector in the rotation drive device 7. The proximal end of the optical fiber 125 is optically connected to the console body 2 via the cable 8. The optical fiber 125 is fixed to the torque wire 121 with an adhesive or the like. The optical fiber 125 is rotatable together with the torque wire 121.

A graded index (GRIN) lens as the condensing optical system 126 and a mirror as the deflecting optical system 127 are fused and connected in series at the tip of the optical fiber 125. The condensing optical system 126 condenses light emitted from the tip of the optical fiber 125. The deflection optical system 127 deflects light emitted from the tip of the optical fiber 125 in the radial direction. The lens (condensing optical system) and the mirror (deflection optical system) are made of quartz glass or borosilicate glass.

The torque wire 121 has a torque wire main body 122. The torque wire body 122 is provided with a flange 123. The torque wire body 122 is a metal and tubular flexible member. The torque wire body 122 has a uniform inner diameter and outer diameter in the longitudinal direction. The torque wire main body 122 encloses an optical fiber 125 that transmits light in the longitudinal direction in a hollow portion, and transmits the rotational force transmitted from the rotation driving device 7 connected to the proximal end to the distal end of the OCT catheter 10. Since the flange 123 in this embodiment is a separate member from the torque wire main body 122, it is easy to form the flange 123 in a desired shape. Further, the flange 123 can be formed of various materials such as a low friction material.

The flange 123 has an outer diameter larger than the outer diameter of the torque wire main body 122. The flange 123 in this embodiment is a tubular member fixed to the torque wire main body 122. The flange 123 is formed with an insertion hole 123a through which the torque wire main body 122 is inserted. A step portion 123b that abuts against the tip of the torque wire main body 122 is formed at the tip of the insertion hole 123a. The torque wire main body 122 and the flange 123 are bonded and fixed in a state where the torque wire main body 122 is in contact with the stepped portion 123b. The flange 123 has a front end 123c in the axial direction and a rear end 123d in the axial direction. A central portion 123e is formed between the front end 123c and the rear end 123d. The end surfaces of the front end 123c and the rear end 123d are both flat surfaces perpendicular to the axial direction. The outer diameters of the front end 123c and the rear end 123d are formed smaller than the outer diameter of the central portion 123e. Moreover, the protrusion part 123f is formed between the front-end | tip 123c and the center part 123e, and between the rear end 123d and the center part 123e, respectively. The protruding portion 123f is annular and has an outer diameter larger than the outer diameter of the central portion 123e.

The exterior body 200 includes a protective tube 240 and a handpiece 230 on the distal end side of the OCT catheter 10. The protective tube 240 is a tubular flexible member and surrounds the torque wire body 122. A predetermined clearance is provided between the inner periphery of the protective tube 240 and the outer periphery of the torque wire body 122. As a result, the torque wire main body 122 is rotatable within the protective tube 240. The protective tube 240 is connected to the rotation drive device 7 at the proximal end. The tip of the protection tube 240 is connected to the handpiece 230.

The handpiece 230 is a portion of the OCT catheter 10 that is gripped by the user. The handpiece 230 includes a substantially cylindrical case body 233 having an internal space S. In the internal space S, a positioning member 234 for fixing the inner body 100 in the radial direction is fixed. In the internal space S of the case body 233, an annular step portion 233a that protrudes from the inner peripheral wall surface toward the radial center is formed. An insertion hole 233b is formed at the rear end of the case body. The distal end side of the protective tube 240 is connected to the insertion hole 233b. The tip of the protective tube 240 extends to the position of the step portion 233a, and is bonded to, for example, the inner peripheral surface of the step portion 233a. From the distal end of the protective tube 240, the distal end side of the torque wire 121 is exposed.

The positioning member 234 is formed by a first member 235 having a substantially cylindrical shape and a second member 236 fitted to the tip of the first member 235. That is, the positioning member 234 has a cylindrical portion 235 a formed by the first member 235 and a wall portion 236 a formed by the second member 236. In the internal space S of the handpiece 230, the wall portion 236a and the step portion 233a face each other in the longitudinal direction of the interior body 100. The wall portion 236a is formed near the tip of the cylindrical portion 235a. The wall portion 236a extends radially inward from the inner peripheral surface of the tubular portion 235a. An insertion hole 236b through which the optical fiber 125 is inserted is formed at the radial center of the wall 236a. Further, the rear end of the wall portion 236a is an end surface 236c exposed in the cylindrical portion 235a. In the present embodiment, the second member 236 is fitted with a protruding piece 235b formed on the first member 235 and extending toward the center in the radial direction. An insertion hole 235c communicating with the insertion hole 236b is formed in the protruding piece 235b.

The needle 250 is fixed to the tip of the insertion hole 236b in the second member 236. The needle 250 is exposed to the outside through an insertion hole 233 c formed at the tip of the case body 233. The needle 250 has a tubular needle body 251 formed of, for example, stainless steel, and a resin coating portion 252 that covers the needle body 251. The needle body 251 includes the distal end side of the optical fiber 125 so as to be rotatable. A slit 251 a is formed at the tip of the needle body 251. From the tip of the needle body 251, the light of the optical fiber 125 can be emitted to the outside.

The flange 123 of the torque wire 121 is disposed between the wall portion 236a and the step portion 233a inside the cylindrical portion 235a. The inner diameter of the cylindrical portion 235a and the outer diameter of the protruding portion 123f of the flange 123 are substantially the same. Thereby, the flange 123 is rotatable in a state where the radial position is constant inside the tubular portion 235a.

Inside the cylindrical portion 235a, a bearing (first bearing) 45 as a friction reducing portion is provided between the wall portion 236a and the flange 123. The bearing 45 has an outer ring 45a and an inner ring 45b disposed inside the outer ring 45a. A rotating body such as a ball (not shown) is arranged between the inner ring 45b and the outer ring 45a. The inner ring 45b is rotatable with respect to the outer ring 45a. In the present embodiment, only the outer ring 45a faces the wall 236a (end surface 236c) side, and the inner ring 45b faces the flange 123 side. The outer diameter of the inner ring 45 b is formed larger than the outer diameter of the tip 123 c of the flange 123. Accordingly, the tip 123c contacts only the inner ring 45b and does not contact the outer ring 45a. Further, the inner diameter of the cylindrical portion 235a and the outer diameter of the bearing 45 are substantially the same. The bearing 45 is movable in the front-rear direction inside the cylindrical portion 235a. An optical fiber 125 is inserted inside the inner ring 45 b of the bearing 45.

Also, a bearing (friction reduction part) 46 is provided between the step part 233a and the flange 123 inside the cylindrical part 235a. The bearing 46 has the same configuration as the bearing 45, and has an outer ring 46a and an inner ring 46b. And only the outer ring | wheel 46a faces the step part 233a side, and the inner ring | wheel 46b faces the flange 123 side. The outer diameter of the inner ring 46 b is formed larger than the outer diameter of the rear end 123 d of the flange 123. Thereby, the rear end 123d of the flange 123 contacts only the inner ring 46b and does not contact the outer ring 46a. An elastic member is disposed between the bearing 46 and the step 233a. That is, the bearing 46 and the elastic member are disposed between the step portion 233a and the flange 123. In the present embodiment, a coil spring 48 is employed as the elastic member.

The natural length of the coil spring 48 is larger than the distance obtained by subtracting the sum of the distances in the front-rear direction of the bearing 45, the flange 123, and the bearing 46 from the distance from the wall 236a (particularly the end surface 236c) to the step 233a. Therefore, in a state where the bearing 45, the flange 123, the bearing 46, and the coil spring 48 are arranged inside the cylindrical portion 235a, the bearing 45, the flange 123, and the bearing 46 are moved to the wall 236a (end surface 236c) side by the coil spring 48. It is pressed. Thereby, the position of the flange 123 in the longitudinal direction of the torque wire 121 is controlled. That is, when an external force is generated in the flange 123 toward the stepped portion 233a, the movement of the flange 123 is restricted by the elastic force (biasing force) of the coil spring 48. Further, when an external force is generated in the flange 123 toward the wall portion 236a, the movement is restricted by the wall portion 236a. Thus, in this embodiment, for example, the flange 123 and the wall portion 236a function as a positioning portion (first positioning portion) that regulates the relative positions of the interior body 100 and the exterior body 200 in the longitudinal direction. Yes. In this case, for example, the position of the tip 123c of the flange 123 in the interior body 100 can be set as the reference position P1 (first reference position). That is, the position shifted rearward from the end surface 236c of the wall 236a in the exterior body 200 by the thickness of the bearing 45 can be set as the reference position P1. At the reference position P1, the positions of the interior body 100 and the exterior body 200 are uniquely determined.

Subsequently, the proximal end side of the OCT catheter 10 will be described. FIG. 3 is an exploded perspective view showing a connector structure on the proximal end side of the OCT catheter 10. FIG. 4 is a cross-sectional view showing the connector structure of the OCT catheter 10. As shown in FIGS. 3 and 4, the connector structure of the OCT catheter 10 includes a connector shell 220, a stopper 30, and a connector 140. The connector shell 220 has an inner space SP extending in the axial direction L, and one end in the axial direction L is open. The connector shell 220 of this embodiment is constituted by a front shell 221 and a rear shell 224. The front shell 221 constitutes the front side of the connector shell 220, has a substantially cylindrical shape, and is gradually narrowed toward the front side. A tubular portion into which the torque wire 121 (see FIG. 7B) is inserted is formed in the inner space SP1 of the front shell 221. A thread 223 for screwing with the rear shell 224 is formed at the rear edge of the front shell 221. A protective tube 240 containing an interior body such as a torque wire is connected to the front end of the front shell 221.

The rear shell 224 has a substantially cylindrical shape and has an inner space SP2 having a substantially circular cross section. A screw groove 225 for screwing with the front shell 221 is formed on the front side of the rear shell 224. The rear shell 224 and the front shell 221 constitute a connector shell 220 when the screw groove 225 and the screw thread 223 are screwed together.

A bearing (second bearing) 50 is disposed between the rear shell 224 and the front shell 221. The bearing 50 is sandwiched between a rear end of the front shell 221 and a step portion 225 a formed on the inner peripheral surface of the rear shell 224, and is fixed in the connector shell 220. The bearing 50 is a so-called ball bearing having an outer ring 51, an inner ring 52 disposed on the inner peripheral side of the outer ring 51, and a plurality of balls 53 sandwiched between the outer ring 51 and the inner ring 52. In the present embodiment, the outer ring 51 is fixed to the connector shell 220, so that the inner ring 52 is rotatable with respect to the connector shell 220.

The rear end 224a of the rear shell 224 is open. In the connector shell 220, the inner space SP2 of the rear shell 224 and the inner space SP1 of the front shell 221 are continuous from the opening of the end 224a. On the outer peripheral surface of the rear shell 224, a positioning protrusion 226 that protrudes radially outward is formed at one place in the circumferential direction. The connector shell 220 is inserted into the connection port 7a in a state where the alignment portions 7b formed in the connection port 7a and the positioning protrusions 226 formed in the connector shell 220 are aligned in the circumferential direction.

A positioning groove 227 extending from the rear end in the axial direction L to the front side is formed on the inner peripheral surface of the rear shell 224 at one place in the circumferential direction. In this embodiment, the positioning groove 227 restricts the rotation of the stopper 30 with respect to the connector shell 220. Further, the circumferential position of the positioning groove 227 and the circumferential position of the positioning protrusion 226 are substantially the same.

A plurality of thick portions 224b extending radially inward are formed on the inner peripheral surface of the rear shell 224. A hole 228 that extends in the axial direction L and opens to the rear side is formed in the thick portion 224b. A step 228 a is formed in the hole 228. The diameter of the rear side (opening side) of the hole 228 is formed larger than the diameter of the front side with the stepped portion 228a as a boundary. In the present embodiment, holes 228 are formed at 120 ° intervals at three locations in the circumferential direction.

In the inner space SP2 of the rear shell 224, a plurality of locking claws 229 extending in the axial direction L are formed. The locking claw 229 has a rod-like base portion 229a extending toward the rear side with a step portion 229c extending radially inward from the inner peripheral surface of the rear shell 224 as a base end. A claw portion 229b protruding radially inward is formed at the rear end of the base portion 229a. In the present embodiment, locking claws 229 are formed at three intervals in the circumferential direction at intervals of 120 °. The locking claw 229 is disposed between the hole 228 and the hole 228 in the circumferential direction.

FIG. 5A is a perspective view showing the stopper 30. As shown in FIGS. 3, 4 and 5A, the stopper 30 is disposed in the inner space SP of the connector shell 220. The stopper 30 restricts the rotation of the connector 140 relative to the connector shell 220. The stopper 30 has a substantially cylindrical shape and has an annular plate-like stopper body 31 at the front end in the axial direction L. The stopper main body 31 is formed with a positioning projection 32 that protrudes radially outward at one place in the circumferential direction. The positioning protrusion 32 is accommodated in a positioning groove 227 formed on the inner peripheral surface of the rear shell 224 and restricts the rotation of the stopper 30 relative to the rear shell 224.

The stopper main body 31 is formed with a plurality of cylindrical shafts 33 protruding forward in the axial direction L. The length of the shaft 33 is the same as the depth of the hole 228 of the rear shell 224, for example. The diameter of the shaft 33 is smaller than the diameter of the front side of the hole 228. In this embodiment, three shafts 33 are formed at 120 ° intervals at three locations in the circumferential direction. In a state where the stopper 30 is disposed in the inner space SP of the connector shell 220, each shaft 33 is inserted through the spring 34 as an elastic member and through the hole 228. The outer diameter of the spring 34 is larger than the diameter on the front side of the hole 228 and smaller than the diameter on the rear side of the hole 228. Therefore, the spring 34 is disposed between the stopper main body 31 and the step portion 228a. Thereby, the stopper 30 is urged toward the rear in the axial direction L by the spring 34.

The stopper body 31 is formed with notches 35 and locking pieces 36 corresponding to the locking claws 229 at three locations in the circumferential direction. The notch 35 allows the base 229a of the locking claw 229 to be inserted. The locking piece 36 is formed on the radially inner side of the notch 35 so as to engage with the claw portion 229 b of the locking claw 229. In the present embodiment, a locking piece 36 is erected from the stopper main body 31 toward the front in the axial direction L. When the locking piece 36 and the locking claw 229 are engaged, the stopper 30 is prevented from falling off from the connector shell 220. Further, in the natural state, the state in which the locking piece 36 and the locking claw 229 are engaged by the urging of the spring 34 is maintained.

A locking portion 38 protruding inward in the radial direction is formed on the inner peripheral surface 37 of the stopper body 31. In this embodiment, the inner periphery of the stopper main body 31 is formed in a substantially circular shape, and a locking portion 38 is formed at one place in the circumferential direction. That is, the inner diameter of the stopper main body 31 is small only in the circumferential position where the locking portion 38 is formed. The circumferential position of the locking portion 38 is substantially the same as the circumferential position of the positioning protrusion 32.

FIG. 5B is a perspective view showing the connector 140. As shown in FIGS. 3, 4, and 5B, the connector 140 is a so-called SC connector. The connector 140 is disposed in the inner space SP of the connector shell 220 with the connection end 140a facing the opening. The connector 140 includes a ferrule 141 that holds an optical fiber and a housing 142 that houses the ferrule 141. Further, on the front side of the housing 142, a cylindrical housing portion 144 that houses a joint 143 provided at the front end of the ferrule 141 is provided. The joint 143 is connected to, for example, the torque wire 121 (see FIG. 7B). The optical fiber held by the ferrule 141 rotates with the rotation of the housing 142. In the illustrated example, a spring 145 that urges the ferrule 141 in the axial direction L is disposed in the housing 142.

The outer periphery of the accommodating portion 144 is supported by the inner periphery of the inner ring 52 that constitutes the bearing 50. Thus, the connector 140 is disposed in the connector shell 220 so as to be rotatable about the axis. In the present embodiment, the bearing 50 functions as a positioning portion (second positioning portion) that regulates the relative positions of the interior body 100 and the exterior body 200 in the longitudinal direction. In this case, for example, an arbitrary position of the bearing 50 can be set as the reference position P2 (second reference position). In the illustrated example, the position of the front end face of the bearing 50 is the reference position P2. This position is the position of the rear end of the front shell 221, and is the position of the front end of the fixed portion between the bearing 50 and the connector 140.

The housing 142 has a locked portion 147 a that can be engaged with the locking portion 38 formed in the stopper main body 31. Specifically, the housing 142 of the present embodiment is formed with a protrusion 146 used for positioning when connected to the adapter. The connection end 140a side of the housing 142 has a substantially rectangular cross section. The protrusion 146 protrudes outward in the radial direction. The housing 142 is formed with a substantially circular plate-shaped rotation restricting portion 147 whose axial direction L is the thickness direction. A locked portion 147 a that is recessed radially inward is formed on the outer periphery of the rotation restricting portion 147. The outer periphery of the rotation restricting portion 147 of the housing 142 and the inner periphery of the stopper main body 31 have the same shape. Further, the thickness in the axial direction L of the rotation restricting portion 147 and the thickness in the axial direction L of the stopper main body 31 are substantially the same. In the axial direction L, the position of the rotation restricting portion 147 of the housing 142 is set to coincide with the position of the stopper main body 31 in a state where the locking piece 36 and the claw portion 229b are in contact with each other. Therefore, as shown in FIG. 4, the rotation restricting portion 147 can be accommodated inside the inner periphery of the stopper main body 31 in a state where the locking piece 36 and the claw portion 229 b are in contact with each other. In this state, the locked portion 147a is locked to the locking portion 38, so that the rotation of the connector 140 relative to the stopper 30 is restricted.

Here, the operation of the connector structure of the OCT catheter 10 will be described with reference to FIGS. 6A and 6B. In the OCT catheter 10, the connector 140 is connected to the adapter 7 d of the rotation drive device 7 by pushing the end 224 a side of the connector shell 220 into the connection port 7 a of the rotation drive device 7. FIG. 6A shows a state before the connector shell 220 is pushed into the connection port 7 a of the rotation drive device 7. In FIG. 6A and FIG. 6B, the housing of the rotary drive device 7 is omitted. Therefore, as the rotation drive device 7, only the pressing part 7c fixed in the connection port 7a is shown. The pressing portion 7c has a cylindrical shape, for example. The pressing portion 7 c can be inserted into the inner space SP of the connector shell 220. The pressing part 7c has the same outer diameter as the stopper 30, for example. An adapter 7d connected to the connector 140 is disposed inside the pressing portion 7c. In the rotation drive device 7, the rotation position of the adapter 7 d before the connector shell 220 is pushed in corresponds to the rotation position of the connector 140 in a state where the rotation is restricted by the stopper 30.

The connector 140 is connected by pushing the connector shell 220 into the connection port 7a. At this time, the rotational position of the connector shell 220 is adjusted so that the positioning protrusion 226 of the connector shell 220 is aligned with the alignment portion 7b of the connection port 7a. When the connector shell 220 is pushed into the connection port 7a, first, the front end of the pressing portion 7c and the rear end of the stopper 30 come into contact with each other. When the connector shell 220 is further pushed from this state, the stopper 30 is pushed forward by the pressing portion 7c. The stopper 30 moves forward relative to the connector shell 220 against the biasing force of the spring 34. At this time, the spring 34 is contracted by elastic deformation. Since there is no change in the position of the connector 140 in the axial direction L with respect to the connector shell 220, the stopper 30 also moves forward relative to the connector 140.

As shown in FIG. 6B, in the axial direction L, when the rear end surface 31a of the stopper main body 31 moves further forward than the front end surface 147b of the rotation restricting portion 147, the engagement between the locking portion 38 and the locked portion 147a. The match is released. That is, the restriction on the rotation of the connector 140 by the stopper 30 is released, and the connector 140 becomes rotatable. In this state, the connector 140 is connected to the adapter 7d, and the connector 140 can rotate as the adapter 7d rotates.

The rotational position of the adapter 7d when the connector shell 220 is removed from the connection port 7a is controlled by the rotational drive device 7 so as to be the same as the rotational position of the adapter 7d before the connector shell 220 is pushed. Therefore, when the connector shell 220 is removed from the connection port 7a, the rotation of the connector 140 can be restricted again by the stopper 30.

Subsequently, the relationship between the longitudinal lengths of the inner body 100 and the outer body 200 in the OCT catheter will be described. FIG. 7A is a schematic diagram showing an exterior body of an OCT catheter. In FIG. 7A, the exterior body 200 including the connector shell 220, the protective tube 240, the handpiece 230, and the needle 250 is linearly arranged in the longitudinal direction. FIG. 7B is a schematic view showing the inner body of the OCT catheter. In FIG. 7B, the interior body 100 including the connector 140, the torque wire 121, and the optical fiber 125 is linearly arranged in the longitudinal direction. As shown in FIGS. 7A and 7B, the length B of the interior body 100 from the reference position P1 to the reference position P2 is longer than the length A of the exterior body 200 from the reference position P1 to the reference position P2. . In the present embodiment, for example, the length B of the interior body 100 is 0.1 to 1% longer than the length A of the exterior body 200. In the present embodiment, as an example, when the length A of the exterior body 200 is 2000 mm, the length B of the interior body 100 is 2002 to 2020 mm.

In such an OCT catheter 10, the relative position in the longitudinal direction between the inner body 100 and the outer body 200 is controlled so as not to shift at the reference position P1 and the reference position P2. Therefore, even when an optical coherence tomographic image at a predetermined position is acquired, the optical fiber 125 is suppressed from being shifted in the longitudinal direction. The length of the interior body 100 is longer than the length of the exterior body 200 in the range from the reference position P1 to the reference position P2. Thereby, the inner body 100 including the optical fiber 125 can be disposed in a slack state in the inner space of the outer body 200 (protective tube 240). Thereby, even if the exterior body 200 such as the protective tube 240 is extended by an external force or the like, the external force applied to the exterior body 200 is not easily transmitted to the interior body 100. Therefore, fluctuations in the optical path length hardly occur, and an optical coherence tomographic image can be acquired stably.

Also, for example, in a state where the protective tube 240 is bent, an external force is generated to draw the torque wire 121 and the optical fiber 125 arranged inside the protective tube 240 inside the protective tube 240. In this case, if the length of the interior body 100 and the length of the exterior body 200 are the same, tension is applied to the torque wire 121 and the optical fiber 125 so as to extend them, and the torque wire 121 and the optical fiber 125 are stretched. May extend. However, when the interior body 100 is formed long, even if a pulling force is applied to the interior body 100, no tension is applied to the interior body 100 until the slack of the interior body 100 is fully extended.

Further, in the present embodiment, the length of the interior body 100 is 0.1 to 1% or more longer than the length of the exterior body 200. Thus, since the interior body 100 is not too long, it is suppressed that the inner side of the exterior body 200 and an interior body interfere more than necessary. Moreover, usually, when the interior body and the exterior body are manufactured so as to have the same length, the length of the interior body is 0.1% or more longer than the exterior body even in consideration of manufacturing errors. Very Hard to think. In this embodiment, the influence which the deformation | transformation of an exterior body gives to an interior body is suppressed by making the length of an interior body 0.1% or more longer than the length of an exterior body.

The embodiment of the present invention has been described in detail above with reference to the drawings, but the specific configuration is not limited to this embodiment.

For example, although the example in which the flange 123 and the torque wire main body 122 are configured by separate members is shown, the flange and the torque wire main body may be formed integrally.

Further, the configuration of the stopper 30 or the like is not essential, and the OCT catheter may not have the configuration.

DESCRIPTION OF SYMBOLS 1 ... Medical imaging system, 10 ... OCT catheter, 100 ... Interior body, 125 ... Optical fiber, 200 ... Exterior body, 220 ... Connector shell (2nd exterior body), 230 ... Handpiece (1st exterior body), 240 ... Protection tube (tube), P1 ... first reference position, P2 ... second reference position.

Claims

An interior body including an optical fiber that transmits light and extends in the transmission direction as a longitudinal direction;
A first exterior body covering a longitudinal tip of the interior body, a second exterior body covering a longitudinal end of the interior body, and the first exterior body and the second exterior body connected to the first exterior body An exterior body including a tube covering the interior body;
A first positioning portion that regulates the position of the interior body and the first exterior body in the longitudinal direction at a first reference position;
A second positioning part that regulates the position of the interior body and the second exterior body in the longitudinal direction at a second reference position;
The length of the interior body from the first reference position to the second reference position is longer than the length of the exterior body from the first reference position to the second reference position.
OCT catheter.
The interior body has a torque wire that transmits rotation from the base end in the longitudinal direction to the tip end,
The optical fiber is included in a hollow portion of the torque wire.
The OCT catheter according to claim 1.
The length of the interior body from the first reference position to the second reference position is 0.1 to 1% longer than the length of the exterior body from the first reference position to the second reference position.
The OCT catheter according to claim 1 or 2.
The first positioning portion includes a flange of a torque wire that transmits rotation from a base end in a longitudinal direction to a tip end of the interior body, and a wall portion of the exterior body that faces the flange in the longitudinal direction.
The OCT catheter according to any one of claims 1 to 3.
The first positioning part includes a first bearing disposed between the flange and the wall part,
The OCT catheter according to claim 4.
The flange is biased toward the wall by an elastic member,
The OCT catheter according to claim 4 or 5.
The first exterior body includes a needle that covers a tip of the optical fiber.
The OCT catheter according to any one of claims 1 to 6.
The second positioning portion includes a second bearing that rotatably supports the inner body inside the second outer body.
The OCT catheter according to any one of claims 1 to 7.
The inner body includes a connector that holds a proximal end of the optical fiber,
The connector is rotatably supported by the second bearing;
The OCT catheter according to claim 8.
The second exterior body includes a rear shell disposed at a base end in a longitudinal direction, and a front shell disposed at a distal end in a longitudinal direction rather than the rear shell,
The second bearing is sandwiched between the rear shell and the front shell;
The OCT catheter according to claim 8 or 9.
The interior body is arranged in a slack state in the internal space of the exterior body,
The OCT catheter according to any one of claims 1 to 10.
The interior body is 2 to 20 mm longer than the exterior body,
The OCT catheter according to any one of claims 1 to 11.