JP2008142443A - Optical tomographic apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent the fluctuation of an interference signal level due to the swing of an optical probe in an optical tomographic apparatus. <P>SOLUTION: The optical tomographic apparatus 1, in which the optical probe 10 housing an optical fiber 12 to be inserted into a subject is connected to an optical tomograph main body 1A, is provided with a fixing means 5A for fixing at least a part of the portion extending to the outside of the subject H of the optical probe 10 at least when acquiring optical tomographic images. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an optical tomographic imaging apparatus that generates an optical tomographic image by OCT (Optical Coherence Tomography) measurement, and more particularly to a fixing means for the optical probe.

  Conventionally, when an optical tomographic image of a living tissue is acquired, an optical tomographic image acquisition device using OCT measurement is sometimes used. It is applied to various parts such as observation of the fundus, anterior eye, skin, arterial blood vessel wall using a fiber probe, and observation of a digestive tract in which a fiber probe is inserted from a forceps channel of an endoscope. This optical tomographic image acquisition apparatus divides low-coherent light emitted from a light source into measurement light and reference light, and then reflects or backscattered light from the measurement object when the measurement light is applied to the measurement object. And the reference light are combined, and an optical tomographic image is acquired based on the intensity of the interference light between the reflected light and the reference light.

  The OCT measurement is roughly divided into two types: TD-OCT (Time domain OCT) measurement and FD (Fourier Domain) -OCT measurement. The TD-OCT (Time domain OCT) measurement shown in Patent Document 1 measures the position in the depth direction of the measurement target (hereinafter referred to as the depth position) by measuring the interference light intensity while changing the optical path length of the reference light. Is a method for obtaining a reflected light intensity distribution corresponding to the above.

  On the other hand, FD (Fourier Domain) -OCT measurement measures the interference light intensity for each spectral component of the light without changing the optical path lengths of the reference light and signal light, and uses the obtained spectral interference intensity signal as a computer. In this method, the reflected light intensity distribution corresponding to the depth position is obtained by performing frequency analysis represented by Fourier transform. In recent years, it has attracted attention as a technique that enables high-speed measurement by eliminating the need for mechanical scanning existing in TD-OCT.

  Typical examples of the device configuration for performing FD (Fourier Domain) -OCT measurement include an SD-OCT (Spectral Domain OCT) device and an SS-OCT (Swept source OCT). Among these, the SS-OCT device emits laser light whose wavelength is swept in time from the light source unit, causes reflected light and reference light to interfere at each wavelength, and the signal time corresponding to the time change of the optical frequency. An optical tomographic image is constructed by measuring a waveform and Fourier-transforming a spectrum interference intensity signal obtained thereby by a computer (see Patent Document 2).

  As shown in FIG. 33, the optical tomographic imaging apparatus of each system as described above generally has a flexible elongated optical probe that incorporates a rotating mirror at the tip and accommodates an optical fiber therein. Is connected to the optical tomographic imaging apparatus main body via a coupling optical fiber, and this optical probe is inserted into a measurement object via a guide such as a forceps port of an endoscope scope, for example. The measurement light input from the optical tomographic imaging apparatus main body through the coupling optical fiber is irradiated to the measurement object, and the reflected light from the measurement target of the measurement light is irradiated through the coupling optical fiber to the optical tomographic imaging apparatus main body. Output to. As a result, an optical tomographic image to be measured is acquired.

The optical probe has a portion to be inserted into the measurement target and a predetermined extra length extending outside the measurement target, and can be used for various measurement environments, for example, changes in the insertion amount of the optical probe inserted into the measurement target. The corresponding optical tomographic image can be measured.
JP 2001-264246 A JP 2006-132996 A

  By the way, as shown in FIG. 33, the portion extending out of the measurement target of such an optical probe is used in a suspended state or floating in a space, and the operator can use the optical probe when acquiring an optical tomographic image. When a part inserted into the measurement object is moved in a desired direction or when another device or the like is unexpectedly brought into contact with the optical probe, it is unstablely swayed.

  Since the optical fiber (single mode fiber) accommodated in this optical probe cannot preserve the polarization direction of the guided light, the birefringence of the fiber may change irregularly due to such fluctuation.

  On the other hand, in the OCT measurement, the reflected light from the measurement object and the reference light are combined to generate interference light, but the intensity of the interference light changes according to the polarization direction of the reflected light and the reference light. When the polarization directions match, the intensity of the interference light is maximized. However, as described above, when the birefringence of the fiber changes, the polarization direction of the reflected light or reference light changes, and the intensity of the interference light changes. Such a change in the intensity of the interference light causes fluctuations in the interference signal level when the interference light is detected, causing shading unevenness in the tomographic image and degrading the image quality. Depending on the degree of deterioration in image quality, a problem arises in that it would not be possible to identify what would otherwise be identified.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an optical tomographic imaging apparatus that can prevent a fluctuation of an interference signal level due to a fluctuation of an optical probe and can acquire a tomographic image with good image quality.

  An optical tomographic imaging apparatus according to the present invention is an optical tomographic imaging apparatus in which an optical probe containing an optical fiber inserted into a measurement target is connected to the optical tomographic imaging apparatus main body. And a first fixing means for fixing at least a part of the at least one portion extending when the optical tomographic image is acquired.

  The first fixing means may fix the entire portion of the optical probe extending outside the measurement target at least when acquiring the optical tomographic image.

  When the optical probe is connected to the optical tomographic imaging apparatus main body via a coupling optical fiber, the optical tomographic imaging apparatus fixes at least a part of the coupling optical fiber at least when the optical tomographic image is acquired. A second fixing unit may be provided.

  The second fixing means may fix the entire coupling optical fiber at least when acquiring the optical tomographic image.

  The optical tomographic imaging apparatus includes a rotation drive unit that rotates an optical fiber connected to the optical probe, and a third fixing unit that fixes the rotation drive unit at least when the optical tomographic image is acquired. It may be a thing.

  The first fixing means may include a cylindrical portion having a variable length extending along the optical probe.

  The second fixing means may include a variable-length cylindrical portion extending along the coupling optical fiber.

  The first fixing means may have an exposed portion that exposes a part of the optical probe.

  The portion of the optical probe that extends outside the measurement target means a portion that extends outside the guide unit when the optical probe is introduced into the guide unit such as an endoscope and inserted into the measurement target. .

  According to the optical tomographic imaging apparatus of the present invention, when an optical tomographic image is acquired by including a fixing unit that fixes at least a part of the optical probe extending outside the measurement target at least when the optical tomographic image is acquired. In addition, even when an unintended external force is generated in a portion extending outside the measurement target of the optical probe, the fluctuation of the birefringence of the optical fiber of the optical probe can be reduced by suppressing the fluctuation of the optical probe due to the external force, A tomographic image with good image quality can be acquired.

  If the first fixing means fixes the entire portion extending outside the measurement target of the optical probe at least when acquiring the optical tomographic image, it is excluded from the measurement target of the optical probe when acquiring the optical tomographic image. Even when an unintended external force is generated in the extended portion, since this portion is fixed, the birefringence of the optical fiber of the optical probe can be maintained constant, and a tomographic image with a better image quality can be acquired.

  An optical probe is connected to the optical tomographic imaging apparatus main body via a coupling optical fiber, and the optical tomographic imaging apparatus fixes at least a part of the coupling optical fiber at least when the optical tomographic image is acquired. If an optical tomographic image is acquired, even if an unintended external force is generated in the coupling optical fiber, the coupling optical fiber is prevented from shaking due to the external force, and the birefringence of the coupling optical fiber is suppressed. The tomographic image with good image quality can be acquired.

  If this second fixing means fixes the entire coupled optical fiber at least at the time of optical tomographic image acquisition, even when an unintended external force is generated in the coupled optical fiber when acquiring the optical tomographic image, Since this portion is fixed, the birefringence of the coupling optical fiber can be kept constant, and a tomographic image with better image quality can be acquired.

  The optical tomographic imaging apparatus includes a rotary drive unit that rotates an optical fiber connected to an optical probe, and a fixing unit that fixes the rotary drive unit at least when acquiring an optical tomographic image. In this case, even when an unintended external force is generated in the rotary drive unit, the optical drive connected to the rotary drive unit and the optical probe connected to the rotary drive unit can be prevented from shaking, and a tomographic image with good image quality can be obtained. An apparatus can be realized.

  When both the first fixing means and the second fixing means include a cylindrical portion having a variable length extending along the internal optical probe or the connecting optical fiber, the optical probes or the connecting optical fibers having different lengths are used. Can also be used widely.

  If the first fixing means has an exposed portion that exposes a part of the optical probe, the optical probe can be operated from the exposed portion in the axial direction of the optical probe.

  Embodiments of an optical tomographic imaging apparatus according to the present invention will be described below in detail with reference to the drawings. FIG. 1 is an external perspective view of an embodiment of the optical tomographic imaging apparatus of the present invention, and FIG. 2 is a schematic configuration diagram showing the overall configuration of the embodiment of FIG. In the present embodiment, the optical tomographic imaging apparatus 1 of the present invention is combined with the endoscope apparatus 2, the optical probe 10 of the optical tomographic imaging apparatus 1 is used, and the forceps port of the endoscope scope 110 is used as a guide means. It demonstrates as what was comprised so that it might insert in a body cavity.

  An optical tomographic imaging apparatus 1 includes an optical tomographic imaging apparatus main body 1A, an optical probe 10 that is inserted into a body cavity through a forceps channel from a forceps opening of an endoscope scope 110, and both ends of the optical tomographic imaging apparatus main body. 1A and the optical probe 10 are connected to the optical tomographic imaging apparatus main body 1A and the optical probe 10, and the optical fiber 10 is connected to the proximal end side of the optical probe 10. A rotary driving unit 10A for rotating the fiber 12 and the optical lens 15, and a first fixing means 5A and a second fixing means 5B for fixing the portion of the optical probe 10 extending outside the measurement target H and the whole of the coupling optical fiber FB20, respectively. It is equipped with.

  FIG. 3 is a schematic diagram showing an example of the tip portion of the optical probe 10. The optical probe 10 has a probe outer cylinder (sheath) 11 that incorporates an optical lens 15 at the tip and accommodates an optical fiber 12 therein. The probe outer cylinder (sheath) 11 is made of a material that has flexibility and allows the measurement light L1 and the reflected light L3 to pass therethrough. The probe outer cylinder 11 has a structure in which the tip is closed by a cap 11a. Further, the optical probe 10 detects a contact direction E with the measurement target H in the optical probe 10 when the optical tomographic image P1 is acquired. Is formed.

  The optical fiber 12 guides the measurement light L1 input from the interferometer 20 of the optical tomographic imaging apparatus main body 1A via the coupling optical fiber FB20 to the measurement target H, and the measurement light L1 is irradiated to the measurement target H. The reflected light (backscattered light) L3 from the measurement target H is guided to the interferometer 20 of the optical tomographic imaging apparatus main body 1A through the coupling optical fiber FB20, and the inside of the probe outer cylinder 11 Is housed in. A flexible shaft 13 is fixed to the outer peripheral side of the optical fiber 12, and the optical fiber 12 and the flexible shaft 13 are mechanically connected to the rotation drive unit 10A. The optical fiber 12 and the flexible shaft 13 are rotated in the arrow R1 direction with respect to the probe outer cylinder 11 by the rotation drive unit 10A. The rotation drive unit 10A includes a rotation encoder (not shown), and the rotation control means 10B recognizes the irradiation position of the measurement light L1 based on a signal from the rotation encoder.

  The optical lens 15 has a substantially spherical shape for condensing the measurement light L1 emitted from the optical fiber 12 onto the measurement target H, and condenses the reflected light L3 from the measurement target H to collect the optical fiber 12. Is incident on. Here, the focal length of the optical lens 15 is formed, for example, at a distance D = 3 mm from the optical axis LP of the optical fiber 12 toward the radial direction of the probe outer cylinder 11. The optical lens 15 is fixed to the light emitting end of the optical fiber 12 using a fixing member 14, and when the optical fiber 12 rotates in the direction of arrow R1, the optical lens 15 also rotates integrally in the direction of arrow R1. Therefore, the optical probe 10 irradiates the measurement object H with the measurement light L1 emitted from the optical lens 15 while scanning in the arrow R1 direction (circumferential direction of the probe outer cylinder 11).

  The rotation drive unit 10A is an electric device that transmits electrical signals from the insertion portion 16a to which the optical probe 10 is detachably attached, the insertion portion 16b to which the optical fiber FB20 is inserted, and the rotation control means 10B of the optical tomographic imaging apparatus main body 1A. A housing having a cable insertion portion (not shown) into which the signal cable is inserted is provided. Further, in the inside of the housing, a rotary connector that is arranged coaxially with the optical fiber 12 and rotates the optical fiber 12, a drive motor that drives the rotary connector, and a rotary encoder that detects the rotational position of the rotary connector Etc. are provided.

The drive motor is controlled by the rotation control means 10B of the optical tomographic imaging apparatus main body 1A via an electric signal cable, and the optical fiber 12 and the optical lens 15 are rotated in the direction of the arrow R1 relative to the probe outer cylinder 11 at about 20 Hz, for example. To be controlled. The rotation control means 10B outputs the rotation clock signal R _CLK to the tomographic image processing means 100 when it is determined that the optical fiber 12 has made one rotation based on the rotation angle of the rotary connector detected by the rotary encoder. Yes.

  Since the rotary drive unit 10A is a heavy object including a drive motor, a rotary encoder, and the like inside the casing, for example, the operation unit of the endoscope scope 110, the endoscope device from the endoscope scope 110, and the like. By attaching and fixing to a universal arm extending to the main body 2A, or a free arm whose base end is fixed to the rack 19 or the operating table on which the optical tomographic imaging apparatus main body 1A is placed, It is desirable to hold at least when acquiring an optical tomographic image.

  Further, the first fixing means 5A and the second fixing means 5B for fixing the optical probe 10 or the connecting optical fiber FB20 are inserted into the insertion portions 16a and 16b of the rotational drive unit 10A, respectively, and the internal spaces thereof are connected to the insertion portion 16a. It is provided continuously with the insertion portion 16b.

  The first fixing means 5A includes a length adjusting portion 205A made of a substantially cylindrical bellows formed of a thin film having a plurality of pleats, and an internal space on both sides of the length adjusting portion 205A. A bellows tube portion extending continuously in space, and an exposed portion 307 in which a part of the side surface of the bellows tube portion is cut to expose a part of the optical probe 10 from the first fixing means 5A. The probe 10 is formed so as to cover the entire portion extending outside the forceps opening.

  4 and 5 are enlarged cross-sectional views showing how the length adjusting unit 205A shown in FIG. 1 expands and contracts, and the length adjusting unit 205A is pulled from both sides in the longitudinal direction of the cylinder (center axis direction). Thus, the length can be extended within a predetermined length range, and conversely, the length in the longitudinal direction can be reduced by applying pressure in the longitudinal direction (center axis direction) of the cylindrical shape. FIG. 12 is an enlarged perspective view of the exposed portion 307 shown in FIG.

  The first fixing means 5A includes a length adjusting portion 205A that allows the length extending along the optical probe 10 of the first fixing means 5A to be variable, and a bellows tube portion that is freely deformable and has shape self-holding ability. Accordingly, the first fixing means 5A is bent and deformed and stretched in a desired shape, and is most suitable for acquiring an optical tomographic image in accordance with the length of the optical probe 10 accommodated in the first fixing means 5A. While being able to adjust freely to a preferable state, when acquiring an optical tomographic image, it can fix in the shape. Further, from the exposed portion 307, the exposed optical probe is operated in the axial direction of the optical probe 10 by an operating means for operating the optical probe manually or in the axial direction, and the position of the tip of the optical probe 10 is adjusted. Can do.

  The second fixing means 5B includes a length adjusting portion 205B made of a bellows having a variable length extending along the coupling optical fiber FB20 of the main fixing means 5B, and a bendable and freely self-holding shape extending to both sides thereof. And a connecting bellows tube portion extending from the attachment portion to which the connecting optical fiber FB20 in the optical tomographic image apparatus main body 1A is attached to the insertion portion 16b of the rotary drive unit 10A. Yes.

  As a result, the second fixing means 5B is bent and deformed into a desired shape and expanded and contracted, and an optical tomographic image is acquired in accordance with the length of the coupled optical fiber FB20 accommodated in the second fixing means 5B. It can be freely adjusted to the most preferable state, and can be fixed in its shape when an optical tomographic image is acquired.

  Although the case where the first fixing means 5A and the second fixing means 5B are each provided with the length adjusting portions 205A and 205B made of bellows has been described, the present invention is not limited to this, and the first fixing means 5A is not limited to this. The length of either of the second fixing means 5B may be adjusted. Hereinafter, with reference to FIGS. 6 to 11, several methods for adjusting the length of the first fixing means 5A or the second fixing means 5B will be described as examples.

  For example, as shown in FIGS. 6 and 7, the first fixing means 5A having a substantially tubular shape is connected to two circular pipe portions arranged with a space of a predetermined length and the circular pipe portions. The long hole fixing portion 216 is provided with a long hole-like connection bolt through hole extending in a direction parallel to the axial direction of the first fixing means 5A. The long hole fixing portion 216 is fixed to one circular pipe portion, and the other circular pipe portion is fixed by a connection bolt 217 passing through the connection bolt through hole. Accordingly, when the length of the first fixing means 5A is changed, the other circular pipe portion is moved in the axial direction of the first fixing means 5A within the range of the length of the fixing hole of the long hole fixing portion. By moving it, the length of the first fixing means 5A can be adjusted.

  Also, as shown in FIGS. 8 and 9, the first fixing means 5A having a substantially tubular shape is constituted by two discontinuous circular pipe portions, and at the end of one circular pipe portion, A feed screw portion 226 having a male screw portion on the peripheral wall is formed. Moreover, the rotation sliding part 227 provided with the internal thread part which meshes with the external thread part of the feed screw part 226 on the inner peripheral surface is rotatably connected to the end part of the other circular pipe part. Accordingly, by rotating the rotary sliding portion 227 along the feed screw portion 226, the rotary slide portion 227 and the circular pipe connected to the rotary slide portion 227 are moved with respect to the feed screw portion 226. The length of the first fixing means 5A can be adjusted by sliding in the axial direction of the first fixing means 5A.

  As shown in FIGS. 10 and 11, the telescopic rod 235 </ b> A is formed in a partial region of the first fixing means 5 </ b> A having a substantially tubular shape. Specifically, the first rod 236, the second rod 237 inserted in the first rod 236 so as to be axially slidable, and the second rod 237 are slidable in the axial direction. A first locking mechanism (not shown) that includes an inserted third rod 238 and that can lock the second rod 237 in a desired extended state relative to the first rod 236; And a second locking mechanism (not shown) that can lock the second rod 237 in a desired extended state. As a result, the telescopic rod 235A can be pulled out to an arbitrary length in the axial direction of the first fixing means 5A, and the telescopic rod 235A is reduced in the direction along the first fixing means 5A. By arranging so as to be accommodated, the length of the first fixing means 5A can be adjusted to a desired length.

  Note that all the length adjustment methods described above can be applied and used not only when adjusting the length of the first fixing means 5A but also when adjusting the length of the second fixing means 5B. . In the above-described embodiment, the length of the fixing means 5A, 5B is adjusted by providing a length adjusting portion in a partial region of the first fixing means 5A or the second fixing means 5B. Although the enabling method has been described, the first fixing means 5A or the second fixing means 5B is formed such that the whole fixing means 5A, 5B can be expanded and contracted in the axial direction. The length may be variable without providing a separate length adjusting unit.

  The exposed portion 307 is not limited to one that cuts a part of the side surface of the first fixing means 5A described in the above embodiment and exposes a part of the optical probe 10 from the first fixing means 5A. For example, as shown in FIG. 13, two substantially circular tube-shaped first fixing means 5A are arranged by sandwiching a space 317 having a predetermined length, and an arm connected to the circular tube portions. The optical probe 10 which is configured to include the portion 318 and is accommodated over the internal space of one circular tube portion and the internal space of the other circular tube portion is arranged in both the circular tubes in the space portion 317 having a predetermined length. The optical probe 10 may be exposed in almost all directions except for the arm portion 318 having both ends connected to the portion, and the optical probe 10 can be operated in the axial direction of the optical probe 10 from the exposed portion 317.

  Each of the fixing means 5A and 5B is not limited to the above-described bellows tube, and fixes any portion extending outside the measurement target of the optical probe 10 or the coupling optical fiber FB20 at least when acquiring the optical tomographic image by any method. May be.

  For example, as shown in FIG. 14, a connected optical fiber formed of a material that is flexible and deformable and has a shape self-holding property, such as a tube in which an outer tube of polyethylene is sheathed on an inner tube of aluminum, or a shape-retaining urethane tube The substantially circular fixing means 15A, 15B having an internal space through which the FB 20 or the optical probe 10 can penetrate can be used. The fixing means 15A or 15B is bent and deformed into a desired shape, and the optical probe 10 or the connecting optical fiber FB20 accommodated in the first fixing means 5A or the second fixing means 5B is used to acquire an optical tomographic image. In addition to being able to freely adjust to the most preferable state, at least when acquiring an optical tomographic image, it can be fixed in its shape.

  Further, as the first fixing means 5A and the second fixing means 5B, as shown in FIG. 15, the optical probe 10 or the coupling optical fiber FB20 is partially fixed to a fixing tool such as a free arm 25, and the optical probe 10 A part of the part extending outside the measurement object or a part or the whole of the coupling optical fiber FB20 may be fixed in a desired shape. The fixing means 25 serves as both the first fixing means 5A and the second fixing means 5B, and has a multi-joint arm structure in which a plurality of arms are connected to each other via joint portions, The base end of the multi-indirect arm is fixed to a rack 19 on which the optical tomographic imaging apparatus main body is placed. By adjusting the angle (shape) of the articulated arm of the fixing means 25, the optical probe 10 or the connecting optical fiber FB20 attached thereto can be fixed in the most preferable state for acquiring an optical tomographic image. Further, a rotation driving unit 10A that rotates the optical fiber 10 connected to the optical probe 10 is attached to the fixing means 25 and is fixedly held, and an unintended external force is generated in the rotation driving unit 10A. However, it is possible to prevent the rotation drive unit 10A and the optical probe 10 connected to the rotation drive unit 10A from shaking.

  Hereinafter, the optical tomographic imaging apparatus main body 1A will be described. The optical tomographic imaging apparatus main body 1A includes an interferometer 20, a light source unit 30, a periodic clock generation unit 80, an A / D conversion unit 90, a tomographic image processing unit 100, and the like.

FIG. 16 is a schematic diagram illustrating an example of the light source unit 30. The light source unit 30 is adapted to emit laser light L while sweeping the wavelength at a constant period T _0. Specifically, the light source unit 30 includes a semiconductor optical amplifier (semiconductor gain medium) 311 and an optical fiber FB30, and the optical fiber FB30 is connected to both ends of the semiconductor optical amplifier 311. . The semiconductor optical amplifier 311 has a function of emitting weak emission light to one end side of the optical fiber FB30 by injecting drive current and amplifying light incident from the other end side of the optical fiber FB30. When a drive current is supplied to the semiconductor optical amplifier 311, the laser light L is emitted to the optical fiber FB 30 by an optical resonator formed by the semiconductor optical amplifier 311 and the optical fiber FB 30.

  Further, an optical branching device 312 is coupled to the optical fiber FB30, and a part of the light guided in the optical fiber FB30 is emitted from the optical branching device 312 to the optical fiber FB31 side. Light emitted from the optical fiber FB31 is reflected by a rotating polygon mirror (polygon mirror) 316 via a collimator lens 313, a diffraction grating element 314, and an optical system 315. The reflected light enters the optical fiber FB31 again via the optical system 315, the diffraction grating element 314, and the collimator lens 313.

  Here, the rotary polygon mirror 316 is rotated in the direction of the arrow R30, and the angle of each reflecting surface is changed with respect to the optical axis of the optical system 315. Thereby, only the light of a specific wavelength band among the lights dispersed in the diffraction grating element 314 returns to the optical fiber FB31 again. The wavelength of the light returning to the optical fiber FB31 is determined by the angle between the optical axis of the optical system 315 and the reflecting surface. The light having a specific wavelength incident on the optical fiber FB31 is incident on the optical fiber FB30 from the optical splitter 312 and the laser light L having a specific wavelength is emitted toward the optical fiber FB1a.

Therefore, when the rotary polygon mirror 316 rotates at a constant speed in the direction of the arrow R30, the wavelength λ of the light incident on the optical fiber FB1a again changes with a constant period as time passes. Specifically, as shown in FIG. 17, the light source unit 30 emits light L having a wavelength swept from the minimum sweep wavelength λmin to the maximum sweep wavelength λmax at a constant period T ₀ (for example, about 50 μsec). The light L emitted from the light source unit 30 is branched into the optical fibers FB1b and FB1c by the optical branching unit 2 made of an optical fiber coupler or the like, and is incident on the interferometer 20 and the periodic clock generation unit 80, respectively.

  Although the case where the wavelength is swept by rotating the polygon mirror as the light source unit 30 is illustrated, the light source unit 30 emits light while sweeping the wavelength at a constant period by a known technique such as an ASE light source unit. May be.

  FIG. 18 is a schematic diagram showing an example of the interferometer 20. The interferometer 20 is a Mach-Zehnder type interferometer, and is configured by housing various optical components in a housing 20A. The interferometer 20 divides the light L emitted from the light source unit 30 into measurement light L1 and reference light L2, and the measurement light L1 divided by the light division means 3 is irradiated onto the measurement target H. And combining means 4 for combining the reflected light L3 from the measurement target H and the reference light L2, and detecting the interference light L4 between the reflected light L3 combined by the combining means 4 and the reference light L2. Interference light detecting means 70. The interferometer 20 and the light source unit 30 are connected using an APC (Angled physical contact) connector. By using the APC connector, the reflected return light from the connection end face of the optical connector (optical fiber) can be reduced to the limit, and the deterioration of the image quality of the optical tomographic image P1 can be prevented.

The light splitting means 3 is composed of, for example, a 2 × 2 optical fiber coupler, and splits the light L guided from the light source unit 30 through the optical fiber FB1b into the measurement light L1 and the reference light L2. At this time, the light dividing means 3 divides the light at a ratio of, for example, measurement light L1: reference light L2 = 99: 1. The light splitting means 3 is optically connected to each of the two optical fibers FB2 and FB3. The split measurement light L1 is incident on the optical fiber FB2 side, and the reference light L2 is incident on the optical fiber FB3 side. It is like that.
An optical circulator 21 is connected to the optical fiber FB2, and optical fibers FB4 and FB5 are connected to the optical circulator 21, respectively. The optical fiber FB4 is connected to a coupling optical fiber FB20 that guides the measurement light L1 to the optical probe 10, and the measurement light L1 guided to the optical probe 10 via the coupling optical fiber FB20 is transmitted to the measurement target H. Irradiated. The reflected light L3 from the measurement target of the measurement light L1 detected by the optical probe 10 is guided to the optical fiber FB4 via the coupling optical fiber FB20, is incident on the optical circulator 21, and is transmitted from the optical circulator 21 to the optical fiber FB5. Injected to the side. The optical fiber FB4 and the connecting optical fiber FB20 are connected by using an APC (Angled physical contact) connector, and the reflected return light from the connection end face of the optical connector (optical fiber) is reduced to the limit, so that the optical tomography Image quality deterioration of the image P1 is prevented.

  On the other hand, an optical circulator 22 is connected to the optical fiber FB3, and optical fibers FB6 and FB7 are connected to the optical circulator 22, respectively. The optical fiber FB6 is connected with an optical path length adjusting means 40 for changing the optical path length of the reference light L2 in order to adjust the tomographic image acquisition region. The optical path length adjusting means 40 includes an optical path length rough adjusting optical fiber 40A for coarsely adjusting the optical path length, and an optical path length fine adjusting means 40B for finely adjusting the optical path length.

  One end side of the optical path length coarse adjustment optical fiber 40A is detachably connected to the optical fiber FB2, and the other end side is detachably connected to the optical path length fine adjustment means 40B. A plurality of optical path length rough adjustment optical fibers 40A having different lengths are prepared in advance, and an optical path length rough adjustment optical fiber 40A having an appropriate length is appropriately attached as necessary. The optical path length coarse adjustment optical fiber 40A is connected to the optical fiber FB6 and the optical path length fine adjustment means 40B using an APC (Angled physical contact) connector, and is connected to the end face of the optical connector (optical fiber). The reflected return light is reduced to the limit, and the image quality deterioration of the tomographic image P is prevented.

  The optical path length fine adjustment means 40B includes a reflection mirror 43, an optical terminator 44, and the like. The reflection mirror 43 reflects the reference light L2 emitted from the optical path length coarse adjustment optical fiber 40A to the optical terminator 44 side, and again reflects the reference light L2 reflected from the optical terminator 44 to the optical path length coarse adjustment optical fiber 40A side. Is reflected. The reflecting mirror 43 is fixed on a movable stage (not shown), and the optical path length of the reference light L2 is changed by moving in the optical axis direction (arrow A direction) of the reference light L2 by the mirror moving means. . This movable stage is configured to move the reflecting mirror 43 in the direction of arrow A when the optical path length adjusting operation unit 46 is operated by a doctor or the like.

  Further, a polarization controller 50 is optically connected to the optical fiber FB7. The polarization controller 50 has a function of rotating the polarization direction of the reference light L2. As the polarization controller 50, for example, a known technique such as JP-A-2001-264246 can be used. The polarization controller 50 adjusts the polarization direction by operating the polarization adjustment operation unit 51 by a doctor or the like. For example, the reflected light L3 and the reference light L2 are combined by the combining means 4. By operating the polarization adjustment operation unit 51 so that the respective polarization directions coincide with each other, the tomographic image can be adjusted to be clear.

  The multiplexing means 4 is composed of a 2 × 2 optical fiber coupler, and combines the reflected light L3 guided through the optical fiber FB5 and the reference light L2 guided through the optical fiber FB7. Specifically, the multiplexing unit 4 branches the reflected light L3 guided through the optical fiber FB5 into two optical fibers FB8 and FB9, and the reference light L2 guided through the optical fiber FB7 into two optical fibers FB8, Branch to FB9. Accordingly, the reflected light L3 and the reference light L2 are combined in each of the optical fibers FB8 and FB9, the first interference light L4a is guided in the optical fiber FB8, and the second interference light L4b is guided in the optical fiber FB9. Will wave. That is, the multiplexing unit 4 also functions as an optical branching unit 5 that branches the interference light L4 between the reflected light L3 and the reference light L2 into two interference lights L4a and L4b.

  The interference light detection means 70 includes a first light detection unit 71 that detects the first interference light L4a, a second light detection unit 72 that detects the second interference light L4b, and a first light detection unit 71 detected by the first light detection unit 71. And a differential amplifier 73 that outputs the difference between the first interference light L4a and the second interference light L4b detected by the second light detection unit 72 as the interference signal IS. Each of the light detection units 71 and 72 includes, for example, a photodiode or the like, and photoelectrically converts each of the interference lights L4a and L4b incident via the variable light attenuators 60A and 60B and inputs them to the differential amplifier 73. The difference amplifier 73 amplifies the difference between the interference lights L4a and L4b and outputs it as an interference signal IS. In this way, by performing balance detection on the interference lights L4a and L4b by the differential amplifier 73, in-phase optical noise other than the interference signal IS can be removed while amplifying and outputting the interference signal IS.

    Variable optical attenuators 60A and 60B are provided for the first interference light L4a and the second interference light L4b, respectively, between the optical branching means 5 (the multiplexing means 4) and the interference light detection means 70. The variable optical attenuators 60A and 60B attenuate the light intensity levels of the interference lights L4a and L4b detected by the light detectors 71 and 72 at different attenuation rates for each wavelength band so that the light intensity levels are substantially equal in each wavelength band. Injected to the interference light detection means 70 side.

  In addition, when the characteristic of the light intensity level of each interference light L4a and L4b detected in each light detection part 71 and 72 is constant in all wavelength bands, it is not necessary to make an attenuation factor variable, and it matched it with the characteristic. An attenuator with a constant attenuation rate may be used.

  Further, even if the variable optical attenuators 60A and 60B are not provided, the variable optical attenuators 60A and 60B are unnecessary if the light intensity balance in the optical detection units 71 and 72 is substantially uniform in the entire wavelength band.

  The interference signal IS output from the interference light detection means 70 is amplified by the amplifier 74 and then output to the A / D conversion unit 90 via the signal band filter 75. By providing this signal band filter 75, it is possible to remove noise from the interference signal IS and improve the S / N ratio.

FIG. 19 is a block diagram showing an example of the A / D conversion unit 90. The A / D conversion unit 90 converts the interference signal IS detected by the interference light detection means 70 into a digital signal and outputs the digital signal. The A / D converter 91, the sampling clock generation circuit 92, the control controller 93, Interference signal storage means 94 is provided. The A / D converter 91 converts the interference signal IS output as an analog signal from the interferometer 20 into a digital signal. The A / D converter 91 performs A / D conversion of the interference signal IS based on the sampling clock output from the sampling clock generation circuit 92. The interference signal storage means 94 is composed of, for example, a RAM (Random Access Memory) or the like, and stores the interference signal IS converted into a digital signal. The operations of the A / D converter 91, sampling clock generation circuit 92, and interference signal storage means 94 are controlled by a controller 93.
Here, the interference signal IS that has been stored by the interference signal storage means 94, when the periodic clock signal T _CLK is output, the later the timing of the periodic clock signal T _CLK is outputted by one cycle as reference interference It is acquired by the signal acquisition means 101. If the output timing of the periodic clock signal T _CLK is within the wavelength band to be swept, it may be set to the wavelength immediately after the start of the wavelength sweeping to acquire the interference signal IS for one period, or the wavelength The interference signal IS for one period may be acquired immediately before the end of the sweep.

FIG. 20 is a schematic diagram showing an example of the periodic clock generating means 80 for generating the above-described periodic clock signal _TCLK . The periodic clock generation means 80 outputs one periodic clock signal T _CLK each time the wavelength of the light L emitted from the light source unit 30 is swept by one period. The photodetection unit 84 is provided. Then, the light L emitted from the optical fiber FB 1 c enters the optical filter 82 via the optical lens 81. The light L transmitted through the optical filter 82 is detected by the light detection unit 84 via the optical lens 83, and the periodic clock signal T _CLK is output to the A / D conversion unit 90.

The optical filter 82 is made of, for example, an etalon or the like, and has a light transmission period FSR (free spectrum range) in which one transmission wavelength is set in the wavelength band λmin to λmax among a plurality of transmission wavelengths. Therefore, as shown in FIG. 21, when the light L whose wavelength is swept at a constant period is emitted from the light source unit 30 and the wavelength of the light L becomes the set wavelength λref, the periodic clock signal T _CLK is output. It will be. As shown in FIG. 11, depending on the characteristics of the optical filter (etalon) 82, the transmission band width (FWHM: Full Width at Half Maximum) is widened, and the generation timing of the periodic clock signal _TCLK is the transmission band width. It may shift within the range. In this case, it is preferable that the interference signal acquisition unit 101 described later is accurate and preferable if, for example, the middle of the transmission bandwidth is used as the generation timing of the periodic clock signal _TCLK . Thus, by generating and outputting the periodic clock signal T _CLK using the light L actually emitted from the light source unit 30, the light L emitted from the light source unit 30 has a predetermined light intensity from the start of wavelength sweeping. Even when the time until becomes different for each period, the interference signal IS in the wavelength band of the predetermined period T (see FIG. 7) can be acquired from the set wavelength λref. Therefore, the periodic clock signal _TCLK can be output at the timing of acquiring the interference signal IS in the assumed wavelength band in the tomographic image processing means 100, and degradation in resolution can be suppressed.

  FIG. 22 is a block diagram showing an example of the tomographic image processing means 100. The configuration of the tomographic image processing means 100 as shown in FIG. 22 is realized by executing a tomographic image processing program read into the auxiliary storage device on a computer (for example, a personal computer). The tomographic image processing unit 100 includes an interference signal acquisition unit 101, an interference signal conversion unit 102, an interference signal analysis unit 103, a tomographic image generation unit 105, and the like. have.

As described above, the interference signal acquisition unit 101 stores the interference signal IS for one period detected by the interference light detection unit 70 based on the periodic clock signal _TCLK output from the periodic clock generation unit 80 as an interference signal. It is acquired from the means 94. Specifically, for example, the interference signal acquisition unit 101 acquires an interference signal IS in the wavelength band DT before and after the output timing of the periodic clock signal _TCLK as shown in FIG. Note that the method of acquiring the interference signal IS is not limited to this, and the interference signal acquisition unit 101 only needs to acquire the interference signal IS for one period on the basis of the output timing of the periodic clock signal _TCLK .

  The signal conversion means 102 makes the interference signal IS acquired over time in the A / D conversion unit 90 as shown in FIG. 23 at equal intervals on the wavenumber k (= 2π / λ) axis as shown in FIG. It has the function to rearrange. Specifically, the signal conversion unit 102 has time-wavelength sweep characteristic data or a function of the light source unit 30 in advance, and uses the time-wavelength sweep characteristic data table or the like to be equally spaced on the wavenumber k axis. Thus, the interference signal IS is rearranged. As a result, when calculating tomographic information from the interference signal IS, a spectral analysis method that assumes equal intervals in a frequency space such as a Fourier transform process and a process using the maximum entropy method, etc., at each depth position with high accuracy. Fault information can be obtained. The details of this signal conversion method are disclosed in US Pat. No. 5,956,355.

  The interference signal analysis unit 103 analyzes the signal using a known spectrum analysis technique such as Fourier transform processing, maximum entropy method (MEM), or Yule-Walker method acquired by the interference signal acquisition unit 102, at each depth position. The tomographic information r (z) is calculated.

  The tomographic image generating means 105 uses the optical probe 10 as the tomographic information r (z) for one cycle acquired by the tomographic information acquiring means 104 as tomographic information for one line acquired from each depth position of the measurement target H. By acquiring tomographic information r (z) for a plurality of lines in the radial direction (arrow R1 direction), one tomographic image P1 is generated.

Here, the tomographic image generation means 105 stores the sequentially acquired tomographic information r (z) for one line in the tomographic information storage means 105a, and the rotation clock signal R _CLK is output from the rotation control means 10B. At this time, the tomographic image P1 is generated using the stored tomographic information r (z) for n lines. For example, when the periodic clock signal T _CLK from the light source unit 30 is 20 kHz, and the optical probe 10 scans the measurement light L1 in the direction of the arrow R1 at 20 Hz, the tomographic image generation means 105 has n = 1024 lines. One tomographic image P1 is generated using the tomographic information r (z).

  In order to improve the image quality, a method of acquiring, acquiring and averaging a plurality of tomographic images may be used. That is, when the optical probe 10 irradiates the same part of the measurement target H while scanning the measurement light L1 a plurality of times, the tomographic image generation unit 105 acquires a plurality of tomographic images from the same part. Then, the tomographic image generation unit 105 calculates the average value of the tomographic information r (x, z) at each depth position z at the position x with respect to the length direction of the optical probe 10 using the plurality of tomographic images. Thereby, the noise component contained in each tomographic image is canceled, and a tomographic image with good image quality can be acquired.

  Further, when the tomographic image generation unit 105 generates the tomographic image using the tomographic information r (z) for a plurality of lines in the scanning direction (arrow R1 direction), the tomographic information of a plurality of adjacent lines is averaged. You may make it produce | generate a tomographic image using a thing. The tomographic image generation means 105 uses, for example, tomographic information for three adjacent lines as tomographic information that uses an average value for generating a tomographic image. Thereby, the noise component contained in the tomographic information of each line is canceled, and a tomographic image with good image quality can be generated.

  The image quality correction unit 106 corrects the image quality by performing sharpening processing, smoothing processing, and the like on the tomographic image P generated by the tomographic image generation unit 105. Then, the tomographic image P1 subjected to the image quality correction is output to the data synthesis unit 140.

  The data synthesizing unit 140 synthesizes the endoscope image P1 and the optical tomographic image P2 image data acquired almost simultaneously by the optical tomographic imaging apparatus 1 and the endoscopic imaging apparatus 2 so as to become an operation signal of one screen, The synthesized data is output to the display device 110. Further, the data synthesizing unit 140 includes the position information I of the distal end portion of the endoscope scope 110 acquired by the position detecting unit 4 described later and the measurement (observation) target H in the optical probe 10 acquired by the contact position detecting unit. The contact direction E is recorded as incidental information in the corresponding optical tomographic image P1 and endoscope image P2, and the incidental information can be displayed together with the corresponding image, and can be used for classification and search. Further, the structure of the image displayed on the display device 110 is determined by observing the measurement target, such as determining the attention area Re from the entire area of the optical tomographic image P1 based on the contact direction E, and displaying the determined attention area Re in an enlarged manner. Can be made more suitable.

  For example, when the endoscopic image P1 and the optical tomographic image P2 acquired at substantially the same time are displayed as real-time images on the display screen of the same display device 150, due to the difference in the orientation of both images, An optical tomography in which a measurement (observation) target portion observed in a substantially lower right direction of the endoscopic image shown in (a) of 30 is displayed in a substantially upper left direction in the optical tomographic image shown in (b) of FIG. The image P1 and the endoscope image P2 are displayed in different directions, which may cause confusion during diagnosis. Therefore, the optical tomographic imaging apparatus 1 acquires tomographic images in all directions around the axis of the optical probe 10, but the optical probe 10 is measured on the probe outer cylinder 11 because its focal length is very short ( Observation) A direction E in contact with the object H is detected by the contact position detecting means, and a tomographic image having a predetermined width centered on the direction E in the optical tomographic image P1 shown in FIG. As shown in FIG. 31B, only the attention area Re is always rotated in a fixed direction with respect to the display screen of the display device 110, for example, the lower part of the display screen is rotated in the contact direction E. It can be displayed.

  Specifically, at each depth position, the optical fiber 12 and the optical lens 15 of the optical probe 10 integrally rotate in the circumferential direction (arrow R1 direction) of the probe outer cylinder 11, and the optical lens with respect to the measurement target H. The measurement light L1 emitted from 15 is irradiated while scanning in the circumferential direction (arrow R1 direction) of the probe outer cylinder 11, and tomographic information is acquired in all directions of the optical probe 10. Therefore, as shown in FIGS. 25 and 26, an OCT marker M formed by applying a paint such as black is arranged in a predetermined direction on the probe outer cylinder 11 on the distal end side of the optical probe, and the measurement light in that direction is arranged. Try to block or reflect light. As a result, the OCT marker M is displayed as a black streak or bright line in the acquired optical tomographic image P1 as shown in FIG. 28, so that the direction in which the OCT marker M is formed in the scanning direction can be specified. When the direction Sp of the irradiation light scan start point in the optical tomographic image P1 is the screen upper direction, the direction of the OCT marker image m with reference to the direction Sp of the scan start point is set to, for example, a clockwise angle. It can be easily specified by (φ) or the like.

  Further, the optical probe 10 is formed in a plurality of orientations on the side surface on the distal end side of the probe outer cylinder 11 in order to detect the contact direction E of the optical probe 10 with the measurement target H when acquiring the optical tomographic image P1. A contact position detecting means composed of the contact sensors S0, S15 is formed, and the contact direction E of the optical probe 10 with respect to the measurement target H can be obtained from the output signals from these contact sensors.

  Specifically, as shown in FIGS. 25 to 27, a contact sensor S0 is formed in a direction coinciding with the direction in which the OCT marker M is formed, and a plurality of contact sensors S1, , S15 are arranged at predetermined intervals. Thereby, the position from the contact sensor S0 in each contact sensor, that is, the position from the direction in which the OCT marker M is formed is known. For example, the contact sensor S10 contacts the measurement object H as shown in FIG. When turned ON, it can be easily calculated that the contact sensor S10 is positioned in the direction of the angle (θ) in the clockwise direction from the direction in which the OCT marker M is formed. Furthermore, from the position information (clockwise angle (φ)) of the OCT marker image m with reference to the scan start point direction Sp described above, the direction of the contact sensor S10 with reference to the scan start point of the irradiation light is It can be calculated as the direction of the angle (φ + θ) around, and can be specified as the direction of the contact sensor S10 in contact with the measurement target H, that is, the contact direction E with the measurement target H in the optical probe 10.

  28 and 29 show an optical tomographic image P1 obtained using the optical probe 10. FIG. As shown in FIG. 28, when the scan start point Sp of the irradiation light is on the screen, the lower part of the display screen that is 180 ° clockwise from the scan start point Sp of the irradiation light is in contact with the measurement target H. In order to be in the direction E, the scan start point Sp of the irradiation light is rotated counterclockwise by α (= 180 ° − (φ + θ)), and the lower part of the display screen as shown in FIG. An image that becomes E can be obtained. For example, the direction of the OCT marker image m is the direction of the angle φ = 30 ° in the clockwise direction from the direction of the scan start point, and the direction of the contact sensor S10 that has been turned on in contact with the measurement target H is When the angle θ is 225 ° in the clockwise direction from the direction in which the OCT marker M is formed, the scan start point Sp of the irradiation light is changed clockwise by α = 180− (30 + 225) = − 75 °, that is, By rotating counterclockwise by 75 °, an optical tomographic image in which the lower side of the display screen is in the contact direction E can be obtained.

  In the above description, the scanning start point of the irradiation light is on the screen, and the contact direction E is below the display screen, which is 180 ° clockwise from the scanning start point Sp of the irradiation light. When the angle difference between the direction of the scan start point Sp of the irradiation light and the desired correction direction of the contact direction E is δ, the scan start point Sp of the irradiation light is counterclockwise by α (= δ− (φ + θ)). The optical tomographic image having the contact direction E in the desired correction direction of the display screen can be obtained.

  In this embodiment, the case where the data synthesizing unit 140 is built in the optical tomographic imaging apparatus 1 has been described. However, the data synthesizing unit 140 is built in the endoscope apparatus 2 described later. Alternatively, the optical tomographic imaging apparatus 1 or the endoscope apparatus 2 may be provided as a separate unit.

  Hereinafter, the endoscope apparatus 2 will be described. The endoscope apparatus 2 includes an endoscope apparatus body 2A, an endoscope scope 110, and the like. The endoscope scope 110 includes an operation unit and an insertion unit that is inserted into a body cavity. The universal scope is detachably connected to the endoscope apparatus main body 2A. The operation part has a forceps port for introducing a processing tool such as a forceps or an optical probe, and opens to the distal end of the insertion part through a forceps channel formed from the forceps opening to the entire length of the insertion part. ing. The operation unit includes various buttons such as buttons for instructing the operation so that the distal end of the insertion unit is bent in the vertical direction and the horizontal direction within a predetermined angle range.

  Further, the endoscope scope 110 has a light guide for light transmission and a signal line (coaxial cable) for video signal transmission extending to the tip in the inside thereof, and these light guide and signal line are connection pins of a universal cord. Is connected to the endoscope apparatus main body 2A. Furthermore, an illumination lens optically connected to the scope distal end side of the light guide, a CCD (solid-state imaging device) electrically connected to the scope distal end side of the signal line, and measurement (observation) on the light receiving surface of the CCD And an imaging lens (imaging optical system) that forms an image of reflected light from the object.

  The endoscope apparatus body 2A includes an illumination light unit 120 including a light source that emits white light, and an image processing unit 130 that performs image processing for displaying an image signal based on the captured image as a color image.

  The illumination light unit 120 includes a light source that emits illumination light and a condensing lens that collects light emitted from the light source, and supplies the light generated by the light source to the light guide of the scope via the optical system. It has become. The light from the light guide is irradiated onto the measurement (observation) object through the illumination lens, and the reflected light from the measurement (observation) object is imaged on the light receiving surface of the CCD through the imaging lens, and the result is connected. The image signal is supplied to the image processing means 130 as a time-series video signal.

  The image processing means 130 is an A / D conversion circuit that converts an image signal captured by the endoscope scope 110 into image data that is a digital signal, an image memory that stores the digitized image data, and an output from the image memory. A video signal processing circuit for converting the image data into a video signal and the like, and a data synthesizing unit 140 of the optical tomographic imaging apparatus main body 1A for the endoscope image P2 generated from the image signal captured by the endoscope scope 110. To output.

  Further, the optical tomographic image P1 and the endoscopic image P2 obtained in each of the optical tomographic imaging apparatus 1 and the endoscope apparatus 2 are obtained by detecting them by the position detecting means 4 described later. The position information I of the distal end portion of the endoscope scope 110 in the measurement (observation) target when the images P1 and P2 are acquired can be recorded as supplementary information by the data synthesizing unit 140.

  As the position detection means 4, for example, a measuring device such as a photo interrupter attached to an occlusal guard (mouthpiece) that is sandwiched between the teeth of a patient during an examination may be used. The reflected light from the scale or index formed on the surface is measured, the position of the distal end portion of the endoscope scope 110 is detected, and the obtained position information I of the distal end portion is combined as data that can be used for classification and retrieval. The means 140 is supplied.

  The position detection means 4 drives a plurality of transmission coils built in an insertion tube inserted into the body cavity of the patient, and detects the magnetism of these transmission coils to detect the distal end of the endoscope scope 110. The position of the part may be detected.

  The display device 110 outputs combined data obtained by combining the endoscope image P1 and the optical tomographic image P2 image data into one screen data by the data combining unit 140 on the display screen 150P. On the display screen 150P, the optical tomographic image P1 and the endoscopic image P2 are divided and displayed as real-time images. For example, as shown in FIG. 32, the screen display format is set to a part of the main screen 151, and the sub-screen 152 having an area smaller than that of the main screen 151 is set, and the optical tomographic image P1 (or the internal view) is displayed on the main screen 151. Mirror image P2) can be displayed, and endoscopic image P2 (or optical tomographic image P1) can be displayed on sub-screen 152. Also, the positions and sizes of the sub screen 152 and the main screen 151 can be changed as appropriate, and for example, as shown in FIG. 32B, both images 151 and 152 can be displayed in substantially the same size. Then, a plurality of preset screen display format screens as shown in FIG. 32A or 32B can be switched by a switching button (not shown).

  It should be noted that images taken at substantially the same time among the optical tomographic images P1 and endoscopic images P2 acquired at different photographing intervals for each device by the optical tomographic imaging device 1 and the endoscope image device 2 are displayed. Although the case where the images are displayed on the same display screen has been described, the imaging intervals of the optical tomographic imaging apparatus 1 and the endoscopic imaging apparatus 2 are synchronized, and the images captured simultaneously in both the apparatuses 1 and 2 are recorded in association with each other. It may be displayed on the display screen.

  According to the above-described embodiment, at least a part or the whole of the portion of the optical probe 10 extending outside the measurement target H is fixed at the time of optical tomographic image acquisition, and a part or the whole of the coupling optical fiber FB20. Since the second fixing means 5B for fixing at the time of optical tomographic image acquisition is provided at least, when the optical tomographic image P1 is acquired, an unintended external force is applied to a portion extending outside the measurement target H of the optical probe 10 or to the coupling optical fiber. Even when the optical probe 10 or the coupling optical fiber FB20 is shaken by the external force, the fluctuation of the birefringence of the optical fiber of the optical probe can be reduced, and the optical tomographic image P1 with good image quality can be obtained. You can get it.

  Moreover, even when an unintended external force is generated in the rotational drive unit by providing the rotational drive unit 10A for rotating the optical fiber 12 accommodated in the optical probe 10 at least when acquiring the optical tomographic image, It is possible to realize an optical tomographic imaging apparatus 1 that can prevent shaking of the rotary drive unit and the optical probe connected to the rotary drive unit and obtain an optical tomographic image P1 with good image quality.

  Since both the first fixing means 5A and the second fixing means 5B include a variable-length cylindrical portion extending along the internal optical probe 10 or the connecting optical fiber FB20, the optical probes having different lengths are used. 10 or the connecting optical fiber FB20. Further, the first fixing means 5A has an exposed portion that exposes a part of the optical probe 10, and the optical probe 10 can be operated in the axial direction of the optical probe 10 from the exposed portion.

  In the above embodiment, the case where the optical probe 10 is connected to the optical tomographic imaging apparatus main body 1A via the coupling optical fiber FB20 has been described. However, the optical probe 10 is directly connected to the optical tomographic imaging apparatus. In the case of the optical tomographic imaging apparatus connected to the main body, the second fixing means 5B for fixing the coupling optical fiber FB20 is unnecessary.

  In the optical tomographic image apparatus of the above-described embodiment, a so-called SS-OCT (Swept source OCT) apparatus is used, but another FD-OCT (Fourier Domain OCT) measurement type tomographic image apparatus, TD- Any type of optical tomographic imaging apparatus such as an OCT (Time domain OCT) measurement type tomographic imaging apparatus may be used.

1 is an external perspective view of an embodiment of an optical tomographic imaging apparatus according to the present invention. Schematic configuration diagram showing the overall configuration of the embodiment of FIG. FIG. 2 is a schematic diagram showing an example of a tip portion of an optical probe in the optical tomographic imaging apparatus of FIG. The expanded sectional view which shows 1st Embodiment of the length adjustment part shown in FIG. The expanded sectional view which shows 1st Embodiment of the length adjustment part shown in FIG. (A) is side surface sectional drawing which shows 2nd Embodiment of a length adjustment part, (b) is a top view which shows 2nd Example of a length adjustment part. (A) is side surface sectional drawing which shows 2nd Embodiment of a length adjustment part, (b) is a top view which shows 2nd Embodiment of a length adjustment part. (A) The side view which shows 3rd Embodiment of a length adjustment part, (b) is side sectional drawing which shows 3rd Embodiment of a length adjustment part. (A) The side view which shows 3rd Embodiment of a length adjustment part, (b) is side sectional drawing which shows 3rd Embodiment of a length adjustment part. Side view showing the fourth embodiment of the length adjustment unit Side view showing the fourth embodiment of the length adjustment unit An enlarged perspective view of the exposed portion shown in FIG. The perspective view which shows 2nd Embodiment of an exposed part. External perspective view showing a second embodiment of the fixing means in the optical tomographic imaging apparatus of the present invention External perspective view showing a third embodiment of the fixing means in the optical tomographic imaging apparatus of the present invention. The schematic diagram which shows an example of the light source unit in the optical tomographic imaging apparatus of FIG. The graph which shows a mode that the wavelength of the light inject | emitted from the light source unit of FIG. 16 is swept. Schematic diagram showing an example of an interferometer in the optical tomographic imaging apparatus of FIG. The block diagram which shows an example of the A / D conversion unit in the optical tomographic imaging apparatus of FIG. Schematic diagram showing an example of a periodic clock signal generating means in the optical tomographic imaging apparatus of FIG. The graph which shows an example of the periodic clock signal produced | generated by the periodic clock signal production | generation means of FIG. Block diagram showing an example of the tomographic image processing means of FIG. 22 is a graph showing an example of an interference signal input to the signal conversion unit in FIG. FIG. 22 is a graph showing an example of an interference signal converted by the signal conversion means of FIG. Top view showing the tip side of an optical probe with an OCT marker and contact sensor Side view showing the tip side of an optical probe with an OCT marker and contact sensor The figure which shows the direction where an optical probe touches a measuring object at the time of optical tomographic image acquisition The figure which shows the optical tomographic image obtained by the optical probe of FIG. 2 is a diagram showing an example of an image obtained by rotating the optical tomographic image of FIG. 28 by the data synthesizing means. (A) is explanatory drawing of an endoscopic image, (b) is explanatory drawing of an optical tomographic image. (A) is explanatory drawing of an endoscopic image, (b) is explanatory drawing of an optical tomographic image. The figure which shows an example of the screen display format which displays an endoscopic image and an optical tomographic image on the display apparatus of FIG. The figure for demonstrating the optical tomographic imaging apparatus which concerns on the prior art example of this invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Optical tomographic imaging apparatus 1A Optical tomographic imaging apparatus main body 5A, 15A, 25 Fixing means (1st fixing means)
5B, 15B, 25 Fixing means (second fixing means)
25 fixing means (third fixing means)
DESCRIPTION OF SYMBOLS 10 Optical probe 10A Rotation drive means 12 Optical fiber 20 Interferometer 110 Endoscope scope 205A Length adjustment part 307 Exposure part P1 Optical tomographic image P2 Endoscopic image H Measurement object FB20 Connection optical fiber

Claims (8)

In an optical tomographic imaging apparatus formed by connecting an optical probe containing an optical fiber inserted into a measurement object to the optical tomographic imaging apparatus body,
An optical tomographic imaging apparatus comprising: first fixing means for fixing at least a part of the optical probe extending outside the measurement target at least when acquiring an optical tomographic image.   The optical tomographic imaging apparatus according to claim 1, wherein the first fixing means fixes at least the entire portion of the optical probe extending outside the measurement target at the time of the image acquisition. The optical probe is connected to the optical tomographic imaging apparatus main body via a coupling optical fiber;
3. The optical tomographic imaging apparatus according to claim 1, further comprising a second fixing unit that fixes at least a part of the coupling optical fiber at the time of the image acquisition.   4. The optical tomographic imaging apparatus according to claim 3, wherein the second fixing means fixes the whole of the coupling optical fiber at least at the time of the image acquisition.   The rotation drive unit connected to the optical probe for rotating the optical fiber, and at least third rotation means for fixing the rotation drive unit at the time of the image acquisition. 5. The optical tomographic imaging apparatus according to claim 4.   6. The optical tomographic imaging apparatus according to claim 2, wherein the first fixing means includes a cylindrical portion having a variable length extending along the optical probe.   6. The optical tomographic imaging apparatus according to claim 4, wherein the second fixing means includes a variable-length cylindrical portion extending along the coupling optical fiber.   The optical tomographic imaging apparatus according to claim 2, wherein the first fixing unit has an exposed portion that exposes a part of the optical probe.

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