JP5314296B2 - Optical probe and optical tomographic imaging apparatus for OCT - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make it possible to adjust the length of a sheath at the time of replacement of the sheath and to realize the reproduction of a sufficient watertightness after the replacement of the sheath in an optical probe for OCT. <P>SOLUTION: A seal member 52 is mounted on the center of the outer periphery of a piping tool 51 in which an optical fiber 12 is inserted. The press-fitting part 55 of one end of the piping tool 51 is pressed into the base end of the sheath 11 and the insertion part 56 of the other end of the piping tool 51 is inserted in the almost cylindrical attaching hole 31 of a main body 20 up to a desired position. By inserting the leading end of the sheath 11 in the opening part 58 of a holder 53, the seal member 52 is held between the holder 53 and the main body 20. <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

Description

  The present invention relates to an OCT optical probe and an optical tomographic imaging apparatus that acquires an optical tomographic image using the OCT optical probe.

  Conventionally, when a tomographic image is acquired in a body cavity, an optical tomographic imaging apparatus using OCT measurement is sometimes used. In this optical tomographic imaging apparatus, the low-coherent light emitted from the light source is divided into measurement light and reference light, and then the reflected light and reference light from the measurement object when the measurement light is irradiated onto the measurement object. The optical tomographic image is acquired based on the intensity of the interference light between the reflected light and the reference light. There are two types of OCT measurement: TD (Time Domain) -OCT measurement and FD (Fourier Domain) -OCT measurement. In recent years, FD-OCT measurement has attracted attention as a technique that enables high-speed measurement. Two typical types of optical tomographic imaging apparatuses that perform FD-OCT measurement are an SD (Spectral Domain) -OCT apparatus and an SS (Swept Source) -OCT apparatus.

  In these optical tomographic imaging apparatuses, in order to acquire an optical tomographic image to be measured, which is inserted into a body cavity, the measurement light is guided to scan in at least one dimension, and the reflected light is guided. An optical probe for OCT is used. The OCT optical probe includes a distal end portion inserted into a body cavity and a main body that scans measurement light emitted from the distal end portion. The distal end portion includes an optical fiber, a distal optical system fixed to the distal end of the optical fiber, and a flexible long sheath covering the optical fiber and the distal optical system. Normally, as shown in FIG. 14, the sheath is press-fitted into the base end and fixed with an adhesive or the like.

  When the OCT optical probe is used repeatedly, the sheath may be damaged or buckled due to buckling. The sheath scratch may cause deterioration of the tomographic image, and the sheath bent may make insertion into the body cavity difficult. There is a fear. However, the OCT optical probe is expensive, and only the sheath is replaced from the viewpoint of cost. At the time of replacement, since there is a variation in the length of the sheath to be replaced, it is necessary to adjust the sheath length so that the tip optical system is at a predetermined position in the sheath.

Patent Document 1 discloses a sheath length adjusting mechanism in which a pipe fitting press-fitted into a base end of a sheath is slidably fitted to a fixed pipe screwed to a main body, and the pipe is fixed to the fixed pipe with a set screw. An optical probe for OCT having the following has been proposed. Patent Document 2 proposes an OCT optical probe in which a male thread part is provided in a piping tool and a female thread part is provided in a main body, and the sheath length is adjusted by the amount of screwing into the main body of the piping tool.
JP 2001-87269 A JP 2002-263106 A

  However, since the OCT optical probe is used in a body cavity and is used after being washed with a disinfectant from the viewpoint of preventing secondary infection, water tightness is required. It is important to reproduce watertightness.

  In the technique proposed in Patent Document 1, O-rings are provided between the fixed pipe and the main body and between the fixed pipe and the plumbing fixture, which are required to be watertight. When replacing the sheath, the O-ring between the fixed pipe and the main body is pressed by screwing the fixed pipe into the main body to ensure watertightness between the fixed pipe and the main body. The water tightness between the fixture and the fitting is maintained only by the O-ring between the fixed pipe and the fitting being pressed against the fitting. May be difficult to reproduce.

  In the technique proposed in Patent Document 2, there is no particular proposal for watertightness between the main body and the piping device.

  In view of the above circumstances, the present invention makes it possible to adjust the sheath length of the OCT optical probe when the sheath is replaced, and to realize sufficient watertightness after the replacement of the sheath.

  In order to solve the above problems, an OCT optical probe of the present invention is inserted through an optical fiber in an OCT optical probe that scans light from the tip of the optical fiber in the sheath around the axis of the optical fiber. A plumbing fixture having a main body having a cylindrical mounting hole, a press-fitting portion into which an optical fiber is inserted, press-fitted into a sheath at one end, and an insertion portion capable of being inserted into a desired position of the mounting hole at the other end A seal member attached to the center of the outer periphery of the piping tool, and a holding tool that has an opening at the substantially center, and inserts the opening from the distal end of the sheath to sandwich the seal member with the main body. It is characterized by having. Here, “substantially cylindrical” does not necessarily mean a cylindrical shape having a strictly constant diameter from end to end with a straight axis as the center, but a stepped cylindrical shape having different diameters or a cylindrical shape This includes those having grooves or the like formed on the surface. The “outer periphery center” does not mean the exact center position of the outer periphery of the piping device, but also includes the vicinity of the center position of the outer periphery. The above-mentioned “seal member” means a member that is widely used for sealing, and specifically means an O-ring, Y packing, V packing, and a molded product molded in an optimal shape for sealing. Is. The “substantially center” is not limited to the exact center position, but includes the vicinity of the center position.

  The holder may further have a tapered surface on the main body side of the opening, and the sealing member may be sandwiched between the tapered surface and the main body. Here, the “main body side” means a side facing the main body. The above “having a tapered surface” is not limited to forming the tapered surface by processing the opening, but includes providing other parts having a tapered surface in the opening.

  Further, when the female screw formed in the opening of the holding tool and the male screw formed on the outer periphery of the pipe fitting are screwed together, the holding tool can be moved to the main body side. A sealing member may be sandwiched between the two. Here, “forming at the opening” means forming at the portion of the opening facing the outer periphery of the piping device. The “outer periphery of the piping device” does not mean the entire outer periphery of the piping device, but may be a part of the outer periphery of the piping device.

  Further, the seal member may be sandwiched between the holder and the main body by engaging the protrusion provided on the main body with the hook-shaped engagement groove provided on the holder.

  Further, the seal member may be sandwiched between the holder and the main body by engaging the hook-shaped engagement groove provided on the main body with the protrusion provided on the holder.

  The optical tomographic imaging apparatus according to the present invention is characterized in that the OCT optical probe according to the present invention is used in the optical tomographic imaging apparatus of each measurement method as described above. That is, an optical tomographic imaging apparatus according to the present invention includes a light source unit that emits light, a light dividing unit that divides the light emitted from the light source unit into measurement light and reference light, and irradiates the measurement object with the measurement light. An optical probe for OCT, a multiplexing means for combining the reflected light from the measurement object and the reference light when the measurement object is irradiated with the measurement light, and interference light between the combined reflected light and the reference light Based on the detected interference light frequency and intensity, the reflection intensity at a plurality of depth positions of the measurement object is detected, and based on the intensity of the reflected light at each depth position. In the optical tomographic imaging apparatus comprising a tomographic image processing means for acquiring a tomographic image to be measured, the OCT optical probe includes the OCT optical probe of the present invention.

  The optical probe for OCT of the present invention can be inserted into the cylindrical mounting hole of the main body of the piping tool press-fitted into the sheath to a desired position, and even when the sheath length varies, The sheath length can be adjusted. Further, by inserting a sheath through the opening of the holding tool from the tip, and holding the seal member attached to the center of the outer periphery of the piping tool between the holding tool and the main body side. It is possible to reproduce sufficient water tightness after sheath replacement. Furthermore, by providing a tapered surface on the main body side of the opening of the holder, this tapered surface can press the seal member against both the piping device and the main body.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is an overall perspective view of an optical tomographic imaging apparatus 1 to which an OCT optical probe 2 of the present invention is applied. As shown in FIG. 1, an optical tomographic imaging apparatus 1 includes an optical tomographic processing apparatus 100, a drive unit 60 connected to the optical tomographic processing apparatus 100 by an optical fiber cable 3 and a control cable 4, and the drive unit 60. The OCT optical probe 2 according to the present invention is configured to be detachable.

  The optical fiber cable 3 covers an optical fiber (not shown), and the optical fiber is inserted through the drive unit 60 and the OCT optical probe 2. The drive unit 60 has a rotary connector (not shown) so that the optical fiber in the drive unit 60 and the optical fiber in the OCT optical probe 2 can be attached and detached. Moreover, the drive unit 60 has a drive means (not shown), and rotates the optical fiber via the rotary connector (not shown). The control cable 4 is connected to drive means (not shown) built in the drive unit 60. The OCT optical probe 2 includes a long flexible distal end member 10 and a main body 20 fixed to the proximal end side of the distal end member 10.

  The OCT optical probe 2 will be described in detail. FIG. 2 is a cross-sectional view of the OCT optical probe 2 of the present invention.

  The tip member 10 of the OCT optical probe 2 usually has a length of about 1.6 to 3 m and may be inserted into the body cavity B through the forceps channel of the endoscope. Therefore, the endoscope is not shown. The tip member 10 has a substantially cylindrical sheath 11, an optical fiber 12 that extends in the longitudinal direction of the sheath 11, and a flexible member that covers the optical fiber 12 and is fixed to the optical fiber 12. The optical shaft 13, the tip optical system 14 that collects light emitted from the tip of the optical fiber 12 toward the measurement target M, and the tip optical system 14 that is coaxial with the optical axis LP of the optical fiber 12 are fixed integrally. The ferrule 15 and the like are configured. The ferrule 15 reinforces the holding by holding the optical fiber 12 and the flexible shaft 13 with an adhesive or the like and further fitting with the sleeve 16.

  The sheath 11 is made of a flexible member. In this embodiment, the sheath 11 has a structure in which the distal end of the sheath 11 is closed by a cap 11a. The flexible shaft 13 is composed of a close-contact coil in which a metal wire is wound in a tightly wound manner. The tip optical system 14 has a substantially spherical shape, deflects the measurement light L1 emitted from the optical fiber 12, condenses the measurement light M, and deflects the reflected light L3 from the measurement object M. At the same time, the light is condensed and incident on the optical fiber 12. Here, the focal length of the tip optical system 14 is formed, for example, at a position of about 3 mm from the optical axis LP of the optical fiber 12 toward the radial direction of the sheath 11. The measurement light L1 emitted from the tip optical system 14 is tilted by about 7 degrees from the direction perpendicular to the optical axis LP.

  Here, the operation of the tip member 10 of the OCT optical probe 2 of the present invention will be described. As described above, the optical fiber 12 is connected to drive means built in the drive unit 60, and the optical fiber 12 is rotated in the direction of arrow R around the optical axis LP by this drive means. As the optical fiber 12 rotates about the optical axis LP, the tip optical system 14 fixed to the optical fiber 12 via the ferrule 15 is also rotated in the direction of arrow R about the optical axis LP. Therefore, the OCT optical probe 2 scans the measuring object M with the measuring light L1 emitted from the tip optical system 14 in the direction of the arrow R around the optical axis LP. Note that this rotation is not limited to rotation in a certain direction, but also includes oscillation within a predetermined range.

  The main body 20 of the OCT optical probe 2 will be described. The main body 20 rotates with respect to the fixing member 30 around the optical axis LP of the fixing member 30 and the optical fiber 12 and is mounted on the rotating member 40 connected to the drive unit 60 and the distal end side of the fixing member 30. The holding member 50 holds the proximal end of the sheath 11.

  The fixing member 30 includes an inner sleeve 32 having an attachment hole 31 in which the optical fiber 12 and the flexible shaft 13 penetrate and the holding portion 30 is mounted, and an optical fiber with respect to the inner sleeve 32 outside the inner sleeve 32. An outer sleeve 33 slidably attached in the direction of the optical axis LP of 12, and a rubber sleeve 34 for preventing folding, which is fitted and fixed to the inner sleeve 32, and is provided so as to surround a portion on the proximal end side of the sheath 11; The bearing 35 is received by the inner sleeve 32 and rotatably holds the rotating member 40.

  The rotating member 40 has a flexible shaft 13 fixed thereto, a connecting member 41 through which the optical fiber 12 penetrates, and a proximal end ferrule 42 provided by bonding the proximal end of the optical fiber 12 to the connecting member 41. The connecting member 41 is disposed around the base end side of the connecting member 41 and is connected to the spring 43 for biasing the connecting member 41 toward the base end side, the connection ring 44 connected to the drive unit 60, and the connecting ring 44. It is comprised from the rotation cylinder 45 arrange | positioned so that it may surround.

  The holding member 50 includes a pipe member 51 into which the optical fiber 12 and the flexible shaft 13 are inserted, the proximal end side of which is attached to the attachment hole 31, and the distal end side is press-fitted into the proximal end of the sheath 11. An O-ring 52 attached to the outer peripheral center 57 and a holding tool 53 that is attached to the piping tool 51 and moves toward the inner sleeve 32 to sandwich the O-ring 52 with the inner sleeve 32. Yes.

  Here, the holding member 50 and the exchange of the sheath 11 by the holding member 50 will be described in detail. FIG. 3 is a view showing the first embodiment of the holding member 50. As shown in FIG. 3A, a stepped pin is inserted into the through hole 54 of the piping device 51 in which the O ring 52 is attached to the outer peripheral center 57. The press-fit portion 55 of the piping tool 51 is press-fitted into the proximal end of the sheath 11. In this manner, the piping tool 51 can be press-fitted into the sheath 11 without the optical fiber 12 and the flexible shaft 13 being inserted into the piping tool 51, and workability is improved.

  Next, as shown in FIG. 3B, the insertion portion 56 of the piping tool 51 press-fitted into the sheath 11 is inserted to a predetermined position of the mounting hole 31 formed in the inner sleeve 32. In the present embodiment, the male screw 56b formed on the outer periphery 56a of the insertion portion 56 and the female screw 31b formed on the inner periphery 31a of the mounting hole 31 are screwed to each other so that the structure can be inserted to a desired position. It has become. The male screw 56b does not need to be formed on the entire outer periphery 56a of the insertion portion 56, and may be a part. Similarly, the female screw 31b does not need to be formed on the entire inner periphery 31a of the mounting hole 31, and may be a part thereof.

  Next, as shown in FIG. 3C, the sheath 11 is inserted from the tip into the opening 58 provided in the center of the holder 53. Since the diameter of the opening 58 is larger than the diameter of the press-fit portion 55, the holder 53 can move to the inner sleeve 32 side beyond the press-fit portion 55. In this embodiment, the holding tool 53 moves to the inner sleeve 32 side by screwing with a female screw 58b formed on the inner periphery 58a of the opening 58 and a male screw 51b formed on the outer periphery 51a of the piping tool 51. To do. A tapered surface 59 is formed in the opening 58, and the O-ring 52 is sandwiched between the tapered surface 59 and the inner sleeve 32. Further, the taper surface 59 presses the O-ring in the directions of arrows A and B in the figure, and the O-ring 52 is pressed by both the piping tool 51 and the inner sleeve 32, so that The water tightness between the inner sleeve 32 is reproduced, and the looseness between the insertion portion 56 and the inner sleeve 32 is also reduced. Further, the direction of the arrow R in the figure in which the optical fiber 12 and the flexible shaft 13 are inserted through the female pipe 58b on the inner circumference 58a of the opening 58 and the male screw 51b on the outer circumference 51a of the pipe 51. When the screws are screwed together, the screw structure in which the holding tool 53 moves toward the inner sleeve 32 is used to reduce loosening due to the friction of the rotation of the optical fiber 12 and the flexible shaft 13 that pass through the pipe 51. Is done.

  A second embodiment of the holding unit 50 will be described. FIG. 4 is a diagram illustrating a second embodiment of the holding unit 50. In addition, the part which has the structure same as 1st Embodiment of the base end part 50 attaches | subjects the same code | symbol, and abbreviate | omits the description. In the second embodiment of the holding portion 50, as shown in FIG. 4, a screw hole that penetrates to the side of the mounting hole 31 is provided in the inner sleeve 32, and a fixing screw 31c is screwed into this screw hole. The fixing screw 31c presses the piping tool 51 and fixes the piping tool 51 at a desired position. In the second embodiment, the attachment hole 31 and the insertion portion 56 are not screwed together. However, as in the first embodiment, the female screw 31b and the insertion portion 56 are provided on the inner periphery 31a of the attachment hole 31. A male screw 56b may be formed on the outer periphery 56a. The press-fitting of the press-fitting portion 55 into the sheath 11 and the clamping of the O-ring 52 between the holder 53 and the inner sleeve 32 are the same as in the first embodiment, and the description thereof is omitted.

  A third embodiment of the holding unit 50 will be described. FIG. 5 is a diagram illustrating a third embodiment of the holding unit 50. In addition, the part which has the structure same as 1st Embodiment of the base end part 50 attaches | subjects the same code | symbol, and abbreviate | omits the description. As shown in FIG. 5, in the third embodiment of the holding portion 50, a protrusion 32b is provided on the outer periphery 32a of the inner sleeve 32, a hook-shaped engagement groove 53a is provided on the holder 53, and the protrusion 32b is hook-shaped engagement. The O-ring 52 is sandwiched between the holder 53 and the inner sleeve 32 by being locked in the groove 53a. As shown in FIG. 5A, by inserting the holder 53 from the distal end of the sheath 11 and moving it in the direction of arrow A, the protrusion 32b is engaged with the linear portion 53b of the engagement groove 53a. The holding portion 53 receives the distal end side of the inner sleeve 32 and the tapered surface 59 of the opening 58 presses the O-ring 52. Next, as shown in FIG. 5B, the holder 53 is rotated in the direction of arrow B, and the protrusion 32b is locked to the flange 53c, so that the O between the holder 53 and the inner sleeve 32 is obtained. As in the first embodiment, the ring 52 is clamped, and the O-ring 52 is pressed against both the piping device 51 and the inner sleeve 52 by the tapered surface 59, whereby the piping device 51 and the inner sleeve 32 after the sheath replacement. The watertightness between the two will be reproduced. The press-fitting of the press-fitting part 55 into the sheath 11 and the insertion of the insertion part 56 into the attachment hole 31 are the same as in the first embodiment, and a description thereof will be omitted. Further, the fixing of the insertion portion 56 of the second embodiment to the attachment hole 31 is also applicable to the third embodiment. Furthermore, the protrusion 32b and the engagement groove 53a are not limited to a pair, and may be configured by a plurality of pairs.

  A fourth embodiment of the holding unit 50 will be described. FIG. 6 is a diagram illustrating a fourth embodiment of the holding unit 50. In addition, the part which has the structure same as 1st Embodiment of the base end part 50 attaches | subjects the same code | symbol, and abbreviate | omits the description. As shown in FIG. 6, in the fourth embodiment of the holding portion 50, a hook-shaped engagement groove 32 c is provided on the outer periphery 32 a of the inner sleeve 32, and a protrusion 53 d is provided in the opening 58 of the holder 53. The O-ring 52 is sandwiched between the holder 53 and the inner sleeve 32 by being locked in the hook-shaped engagement groove 32c. As shown in FIG. 6A, the holder 53 is inserted from the distal end of the sheath 11 and moved in the direction of arrow A, thereby engaging the protrusion 53d with the linear portion 32d of the engagement groove 32c. The holding portion 53 receives the distal end side of the inner sleeve 32 and the tapered surface 59 of the opening 58 presses the O-ring 52. Next, as shown in FIG. 5 (B), the holder 53 is rotated in the direction of the arrow B, and the protrusion 53d is locked to the flange 32e, so that the O between the holder 53 and the inner sleeve 32 is obtained. As in the first embodiment, the ring 52 is clamped, and the O-ring 52 is pressed against both the piping device 51 and the inner sleeve 52 by the tapered surface 59, whereby the piping device 51 and the inner sleeve 32 after the sheath replacement. The watertightness between the two will be reproduced. The press-fitting of the press-fitting part 55 into the sheath 11 and the insertion of the insertion part 56 into the attachment hole 31 are the same as in the first embodiment, and a description thereof is omitted. In addition, the fixing of the insertion portion 56 of the second embodiment to the attachment hole 31 is also applicable to the fourth embodiment. Furthermore, the protrusion 53d and the engaging groove 32c are not limited to a pair, and may be configured by a plurality of pairs.

  A fifth embodiment of the holding unit 50 will be described. FIG. 7 is a diagram illustrating a fifth embodiment of the holding unit 50. In addition, the part which has the structure same as 1st Embodiment of the base end part 50 attaches | subjects the same code | symbol, and abbreviate | omits the description. As shown in FIG. 7, in the fifth embodiment of the holding portion 50, a plurality of engaging grooves 32 f and locking grooves 32 g are projected on the outer periphery 32 a of the inner sleeve 32, and the inner sleeve 32 side surface of the holder 53 is projected. A plurality of hook-shaped locking claws 53e are provided, and the claw portion 53f of the engagement claw 53e is locked to the locking groove 32g, whereby the O-ring 52 is sandwiched between the holder 53 and the inner sleeve 32. It is a structure to do. As shown in FIG. 7A, by inserting the holder 53 from the distal end of the sheath 11 and moving it in the direction of arrow A, the locking claw 53e is engaged with the engagement groove 32f. The holding portion 53 receives the distal end side of the inner sleeve 32 and the tapered surface 59 of the opening 58 presses the O-ring 52. Next, as shown in FIG. 7B, the holder 53 is rotated in the direction of arrow B, and the claw portion 53f of the locking claw 53e is locked in the locking groove 32g. The O-ring 52 is sandwiched between the sleeve 32 and, as in the first embodiment, the O-ring 52 is pressed against both the piping device 51 and the inner sleeve 32 by the tapered surface 59, so that the sheath after the sheath replacement is changed. The watertightness between the piping tool 51 and the inner sleeve 32 is reproduced. The press-fitting of the press-fitting part 55 into the sheath 11 and the insertion of the insertion part 56 into the attachment hole 31 are the same as in the first embodiment, and a description thereof is omitted. The fixing of the insertion portion 56 of the second embodiment to the mounting hole 31 can also be applied to the fifth embodiment. In the present embodiment, the locking claws 53e, the engaging grooves 32f, and the locking grooves 32g are configured to have three pairs arranged at equal intervals of 120 degrees, but are not limited thereto.

The optical tomography processing apparatus 100 will be described. FIG. 8 is a schematic configuration diagram of the optical tomographic imaging apparatus 1. An optical tomography processing apparatus 100 shown in FIG. 8 is an optical tomography processing apparatus based on SS-OCT measurement, and includes a light source means 110 that emits laser light L and an optical fiber coupler that divides the laser light L emitted from the light source means. 101, a periodic clock generating means 120 for outputting a periodic clock signal T _CLK from the laser light divided by the optical fiber coupler 101, one of the laser lights divided by the optical fiber coupler 101, the measuring light L1 and the reference light L2 The light splitting means 102 for splitting the optical path length, the optical path length adjusting means 130 for adjusting the optical path length of the reference light L2 split by the light splitting means 102, the reflected light L3 from the OCT optical probe 2 and the reference light L2. And an interference light detection for detecting the interference light L4 between the reflected light L3 and the reference light L2 multiplexed by the multiplexing means 103. Means 140 and a tomographic image processing means 150 for performing image processing of the measuring object M by frequency analysis of the interference light L4 detected by the interference light detection means 140 and outputting a tomographic image signal St to the display means 160. Have.

  The light source means 110 emits the laser light L while sweeping the wavelength at a constant period T0. Specifically, the light source means 110 includes a semiconductor optical amplifier 111 and optical fibers FB10 connected to both ends of the semiconductor optical amplifier 111. The semiconductor optical amplifier 111 has a function of emitting weak emission light to one end side of the optical fiber FB10 by injecting drive current and amplifying light incident from the other end side of the optical fiber FB10. When a drive current is supplied to the semiconductor optical amplifier 111, a pulsed laser beam L is emitted to the optical fiber FB0 by the optical resonator formed by the semiconductor optical amplifier 111 and the optical fiber FB10. Further, a circulator 112 is coupled to the optical fiber FB10, and a part of the laser light guided in the optical fiber FB10 is emitted from the circulator 112 to the optical fiber FB11 side. The light emitted from the optical fiber FB11 is reflected by the rotary polygon mirror 116 via the collimator lens 113, the diffractive optical element 114, and the optical system 115. The reflected laser light is incident on the optical fiber FB11 again via the optical system 115, the diffractive optical element 114, and the collimator lens 113. Here, the rotating polygonal mirror 116 rotates at a high speed of about 30,000 rpm in the direction of the arrow R1, and the angle of each reflecting surface changes with respect to the optical axis of the optical system 115. Of the laser light dispersed by the diffractive optical element 114, only the laser light in a specific wavelength region is incident on the optical fiber FB11 again. Then, the laser beam in a specific wavelength range that has entered the optical fiber FB11 is incident on the optical fiber FB10 via the circulator 112, and as a result, is emitted to the optical fiber FB0 side. Therefore, when the rotating polygonal mirror 116 rotates at a constant speed in the direction of the arrow R1, the wavelength λ of the laser light incident on the optical fiber FB11 again changes with a constant period as time passes. As shown in FIG. 9, the light source means 110 emits laser light L swept from the minimum sweep wavelength λmin to the maximum sweep wavelength λmax at a constant period T0 (for example, about 50 μsec). This wavelength-swept laser beam L is emitted to the optical fiber FB0 side.

  The optical fiber coupler 101 branches the laser light L incident on the optical fiber FB0 and makes it incident on the optical fibers FB1 and FB5. The laser light L emitted to the optical fiber FB5 is guided to the periodic clock generation unit 120. The laser light emitted to the optical fiber FB1 is guided to the light splitting means 102.

The periodic clock generation means 120 outputs one periodic clock signal _TCLK each time the wavelength of the laser light L emitted from the light source means 110 is swept for one period. The periodic clock generation unit 120 includes optical lenses 121 and 123, an optical filter 122, and a light detection unit 124. Laser light L emitted from the optical fiber FB5 is incident on the optical filter 122 via the optical lens 121. The laser light L that has passed through the optical filter 122 is detected by the light detection unit 124 via the optical lens 123, and the periodic clock signal T _CLK is output to the tomographic image processing means 150. As shown in FIG. 10A, the optical filter 122 has a function of transmitting only the laser light L having the set wavelength λref and shielding the laser light L having other wavelength bands. The optical filter 122 has a light transmission period FSR (free spectrum range) in which one transmission wavelength is set in the wavelength band λmin to λmax among the plurality of transmission wavelengths. Therefore, only the laser light L having the set wavelength λref set within the wavelength band λmin to λmax in which the wavelength of the laser light L emitted from the light source means 110 is swept is transmitted, and the laser light L in other wavelength bands is transmitted. It will be shielded from light. As shown in FIG. 10B, when the laser light L whose wavelength is periodically swept is emitted from the light source means 110 and the wavelength of the laser light L becomes the set wavelength λref, the periodic clock signal T _CLK is output. Will be.

  The light splitting means 102 splits the laser light L guided to the optical fiber FB1 into measurement light L1 and reference light L2. The measurement light L1 is guided by the optical fiber FB2, and the reference light L2 is guided by the optical fiber FB3 and enters the optical path length adjusting unit 130. The optical fiber FB2 is optically connected to the optical fiber 12. In the present embodiment, the light splitting unit 102 also functions as the multiplexing unit 103.

  The optical path length adjusting unit 130 changes the optical path length of the reference light L2 in order to adjust the position at which tomographic image acquisition is started, and reflects the reference light L2 emitted from the optical fiber FB3. 132, a first optical lens 131a disposed between the reflection mirror 132 and the optical fiber FB3, and a second optical lens 131b disposed between the first optical lens 131a and the reflection mirror 132. ing. The reference light L2 emitted from the optical fiber FB3 becomes parallel light by the first optical lens 131a, and is condensed on the reflection mirror 132 by the second optical lens 131b. Thereafter, the reference light L2 reflected by the reflecting mirror 132 becomes parallel light by the second optical lens 131b, and is condensed on the optical fiber FB3 by the first optical lens 131a. Further, the optical path length adjusting means 130 has a base 133 to which the second optical lens 131b and the reflecting mirror 132 are fixed, and a mirror moving means 134 for moving the base 133 in the optical axis direction of the first optical lens 131a. doing. Then, when the base 133 moves in the direction of arrow A, the optical path length of the reference light L2 is changed.

  The multiplexing unit 103 combines the reference light L2 whose optical path length is adjusted by the optical path length adjusting unit 130 and the reflected light L3 from the measurement target M, and interferes with the interference light L4 via the optical fiber FB4. The light is emitted to the light detection means 140.

  The interference light detection means 140 detects the interference light L4 and outputs an interference signal IS. In this apparatus, the interference light L4 is divided into two by the light splitting means 102, guided to the photodetectors 140a and 140b, calculated, and has a mechanism for performing balance detection. The interference signal IS is output to the tomographic image processing means 150.

  FIG. 11 is a schematic configuration diagram of the tomographic image processing means 150. The tomographic image processing means 150 outputs a tomographic image signal St based on the interference signal IS. The tomographic image processing unit 150 includes an interference signal acquisition unit 151, an interference signal conversion unit 152, an interference signal analysis unit 153, a tomographic image information generation unit 154, an image correction unit 155, and a rotation control unit 156.

The interference signal acquisition unit 151 acquires the interference signal IS for one cycle detected by the interference light detection unit 140 based on the periodic clock signal T _CLK from the periodic clock generation unit 120. The interference signal acquisition unit 151 acquires the interference signal IS in the wavelength band DT (see FIG. 10B) before and after the output timing of the periodic clock signal _TCLK .

  The interference signal conversion means 152 rearranges the interference signals IS acquired by the interference signal acquisition means 151 so that they are equidistant on the wave number (= 2π / λ) axis. FIG. 12A shows the interference signal IS. FIG. 12B shows the rearranged interference signal IS. Specifically, the interference signal converting means 152 has a time-wavelength sweep characteristic data table or function of the light source means 110 in advance, and the time-wavelength sweep characteristic data table or the like is used at equal intervals on the wavenumber k axis. The interference signal IS is rearranged so that

  The interference signal analysis unit 153 obtains the tomographic information It by a known spectrum analysis technique such as Fourier transform processing or maximum entropy method on the interference signal IS converted by the interference signal conversion unit 152.

The rotation control means 156 controls the drive means built in the drive unit 60. Specifically, the rotation control unit 156 outputs a control signal MC for a drive source such as a motor included in the drive unit, and also receives a rotation signal RS from an encoder included in the drive unit. The rotation signal RS includes a rotation clock signal R _CLK and a rotation angle signal R _POS when the drive source makes one rotation.

The tomographic information generation unit 154 acquires the tomographic information It for one period (one line) acquired by the interference signal analysis unit 153 for the radial scanning of the distal end member 10 of the OCT optical probe 2. FIG. 13 is a diagram schematically illustrating the processing of the tomographic information generation unit 154. The tomographic information generating unit 154 stores the tomographic information It for one line acquired sequentially in the tomographic information accumulating unit 154a. The tomographic information generating means 154 reads the tomographic information It from the tomographic information accumulating means 154a in batches of the tomographic information It for n lines based on the rotation clock signal _RCLK input to the rotation control means 156, and scans in the radial direction. Minute fault information It can be generated. Further, the tomographic information generation means 154 sequentially reads the tomographic information It from the tomographic information storage means 154a based on the rotation angle signal R _POS input to the rotation control means 156, thereby obtaining the tomographic information It for the radial scanning. It can also be generated.

  The image quality correcting unit 155 performs a sharpening process, a smoothing process, and the like on the tomographic information It from the tomographic information generating unit 154 and outputs a tomographic image signal St to the display unit 160.

  The display unit 160 receives the tomographic image signal St from the tomographic image processing unit 150 and displays the tomographic image Pt.

  In the OCT optical probe 2 of the present invention, the insertion length 55 of the piping tool 51 press-fitted into the sheath 11 can be inserted into the mounting hole 31 of the inner sleeve 32 to a desired position, so that the sheath length varies. Even in this case, the tip optical system 14 fixed to the tip of the optical fiber 12 at the time of replacement can be set at a predetermined position in the sheath 11. Further, the sheath 11 is inserted through the opening 58 of the holder 53 from the tip, and the O-ring 52 attached to the outer peripheral center 57 of the pipe 51 is connected to the tapered surface 59 formed in the opening 58 of the holder 53 and the inner surface. By being sandwiched between the sleeve 32 and the tapered surface 59, the O-ring 52 is pressed against both the pipe member 51 and the inner sleeve 52, so that there is sufficient space between the pipe member 51 and the inner sleeve 32 after sheath replacement. Watertightness will be reproduced.

  Therefore, the OCT optical probe 2 of the present invention can adjust the sheath length at the time of sheath replacement, and can reproduce sufficient water tightness after the sheath replacement. In this embodiment, the seal member is described as the O-ring 52. However, the present invention is not limited to this, and a Y-packing, a V-packing, or a molded product molded in an optimal shape for sealing may be used.

  The optical tomographic imaging apparatus 1 according to the present invention also employs the OCT optical probe 2 as described above. Therefore, the sheath length can be adjusted at the time of sheath replacement, and sufficient after the sheath replacement. Can reproduce water tightness.

  In the above description, the SS-OCT apparatus is described as an example of the optical tomography processing apparatus 100 to which the OCT optical probe 2 of the present invention is applied. However, the optical tomography apparatus 100 is applied to an SD-OCT apparatus and a TD-OCT apparatus. It is also possible to do.

1 is an overall perspective view of an optical tomographic imaging apparatus 1 to which an OCT optical probe 2 of the present invention is applied. Sectional drawing of the optical probe 2 for OCT of this invention The figure which shows 1st Embodiment of the holding member 50 The figure which shows 2nd Embodiment of the holding member 50. The figure which shows 3rd Embodiment of the holding member 50. The figure which shows 4th Embodiment of the holding member 50. The figure which shows 5th Embodiment of the holding member 50. Schematic configuration diagram of the optical tomographic imaging apparatus 1 The figure which shows the sweep of the wavelength of the light inject | emitted from the light source means 110 The figure which shows the periodic clock signal produced | generated by the periodic clock generation means 120 Schematic configuration diagram of tomographic image processing means 150 The figure which shows the interference signal IS in the interference signal conversion means 152 The figure which shows typically the process of the tomographic information generation means 154 Diagram showing conventional sheath retention

Explanation of symbols

L Laser light L1 Measurement light L2 Reference light L3 Reflected light L4 Interference light M Measurement object 1 Optical tomographic imaging device 2 Optical probe for OCT 11 Sheath 12 Optical fiber 20 Main body 31 Mounting hole 32 Inner sleeve 32b Protrusion 32c Engaging groove 51 Piping Tool 51a outer periphery 51b male screw 52 O-ring 53 holder 53a engagement groove 53d protrusion 55 press-fitting part 56 insertion part 57 outer periphery center 58 opening part 58b female screw 59 taper surface 100 optical tomographic imaging apparatus 102 light dividing means 103 combining means 110 light source means 140 interference light detection means 150 tomographic image processing means

Claims (6)

In the optical probe for OCT that scans light from the tip of the optical fiber in the sheath around the axis of the optical fiber,
A main body having a substantially cylindrical mounting hole for inserting the optical fiber;
A pipe having an insertion portion through which the optical fiber is inserted, a press-fitting portion that is press-fitted into the proximal end of the sheath at one end, and an insertion portion that can be inserted to a desired position of the attachment hole at the other end;
A seal member attached to the center of the outer periphery of the piping device;
An opening is provided at the approximate center, the opening is inserted from the distal end of the sheath, and the seal member is sandwiched between the main body and the seal member to both the main body and the piping device. A holding tool for pressing between the main body and the piping tool by pressing to fix the piping tool at the desired position of the mounting hole ;
The piping device can be inserted to the desired position by screwing a male screw formed on the outer periphery of the insertion portion of the piping device with a female screw formed on the inner periphery of the mounting hole. A characteristic optical probe for OCT.   The OCT light according to claim 1, wherein the holder further has a tapered surface on the main body side of the opening, and the seal member is sandwiched between the tapered surface and the main body. probe.   When the female screw formed in the opening of the holder and the male screw formed on the outer periphery of the piping tool are screwed together, the holder can be moved to the main body side, and the movement allows The optical probe for OCT according to claim 1, wherein the seal member is sandwiched between a holder and the main body.   The seal member is clamped between the holder and the main body by engaging a protrusion provided on the main body with a hook-shaped engagement groove provided on the holder. The optical probe for OCT according to claim 1 or 2.   The seal member is sandwiched between the holder and the main body by engaging a hook-shaped engagement groove provided on the main body with a protrusion provided on the holder. The optical probe for OCT according to claim 1 or 2. Light source means for emitting light;
A light splitting means for splitting the light emitted from the light source means into measurement light and reference light;
An optical probe for OCT that irradiates the measurement object with the measurement light;
A multiplexing means for multiplexing the reflected light from the measurement object and the reference light when the measurement object is irradiated with the measurement light;
Interference light detection means for detecting interference light between the reflected light and the reference light combined;
Based on the frequency and intensity of the detected interference light, the reflection intensity at a plurality of depth positions of the measurement object is detected, and the tomographic image of the measurement object is obtained based on the intensity of the reflected light at each depth position. In a tomographic image processing apparatus comprising a tomographic image processing means for acquiring,
A tomographic image processing apparatus, wherein the OCT optical probe includes the OCT optical probe according to claim 1.

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