JP2015175737A - information acquisition device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately acquire information of an object with a compact configuration.SOLUTION: An imaging apparatus includes at least one lens 131 having a cylindrical surface or an anamorphic surface, a sheet beam generation optical system 103 for shaping light from a laser source 120 to sheet-like light, and an imaging optical system 150 for condensing Raman scattered light RSL generated by irradiating the sheet-like light on an object. An optical axis OA1 of the sheet beam generation optical system and an optical axis OA2 of the imaging optical system 150 are parallel to each other.

Description

  The present invention relates to an information acquisition apparatus that acquires information on an object.

  Patent Document 1 proposes a microscope in which a light sheet is generated by continuously deflecting illumination light in one direction, and the light sheet is incident on an observation object from a direction perpendicular to the observation direction (the optical axis direction of the camera). Has been. With this configuration, it is possible to observe fluorescence and Raman scattering generated only in the region of the observation object that hits the light sheet, and it is possible to image the internal structure of the observation object.

JP 2012-108491 A

  However, the microscope disclosed in Patent Literature 1 cannot acquire information on internal lesions from the surface of a living body internal tissue, for example, a body organ. In order to acquire an image inside a living body, it is necessary to configure an endoscope. However, in Patent Document 1, a galvano scanner is used for generating a light sheet, and this is used in a small endoscope. It is difficult to place. Further, since it is necessary to make the beam incident from a direction different from the observation direction, it is difficult to apply the structure of Patent Document 1 to an endoscope as it is.

  An object of the present invention is to provide an information acquisition apparatus capable of imaging an object with a small configuration.

  An information acquisition apparatus according to the present invention includes a first optical system that has an optical element including a cylindrical surface or an anamorphic surface, shapes light from a light source into sheet-like light, and irradiates the object with the sheet-like light. A second optical system that collects the scattered light that is generated, and the optical axis of the first optical system and the optical axis of the second optical system are parallel to each other .

  ADVANTAGE OF THE INVENTION According to this invention, the information acquisition apparatus which can image a target object with a small structure can be provided.

It is an optical path figure of the information acquisition device of the present invention. (Example 1) It is a fragmentary sectional view of the information acquisition device of the present invention. (Example 2) It is sectional drawing of the information acquisition apparatus of this invention. (Example 3) It is sectional drawing of the information acquisition apparatus of this invention. (Example 4) It is a top view which shows an example of a prism moving means and a lens moving means. (Example 4)

  Hereinafter, an information acquisition apparatus according to an embodiment of the present invention will be described with reference to the accompanying drawings. The information acquisition device is a device that acquires information on an object and may be an imaging device, but as described in the second embodiment, an imaging element is not essential.

  FIG. 1 is an optical path diagram of the information acquisition apparatus 100A according to the first embodiment that functions as an endoscope. The information acquisition apparatus 100 </ b> A according to the present embodiment images an internal member (hereinafter simply referred to as “object”) 12 inside the external member 10. The external member 10 is, for example, an organ, and the target 12 is a pathological change (affected part) inside the organ, but is not limited thereto.

  The information acquisition apparatus 100A includes a housing 110A, a laser light source 120, an excitation light transmission fiber 121, a sheet beam generation optical system 130, a prism 140, windows 115 and 116, an imaging optical system 150, a filter 160, an imaging element 161, and a processing / control system. 170.

  The housing 110 </ b> A includes a first storage unit 111 that stores the sheet beam generation optical system 130 and the prism 140, and a second storage unit 112 that stores the imaging optical system 150, the filter 160, and the imaging element 161. Further, a step is provided between the first storage portion 111 and the second storage portion 112, and a third storage portion in which the external member 10 having the object 12 inside is disposed is formed outside by using the step. Has been.

  The casing 110 </ b> A is configured by an exterior member 114 as a light shielding member, and windows 115 and 116 that transmit light are provided in the exterior member 114 connected to the third storage portion 113.

  The angle (step angle) between the exterior member 114a provided with the stepped window 115 and the exterior member 114b provided with the window 116 is 90 degrees (right angle), which will be described later with reference to FIG. As such, it is not limited to this.

  In this embodiment, the information acquisition apparatus 100A is used in close contact with an organ (external member 10). For this reason, the sushi moving means which moves the whole housing 110A with respect to the external member 10 is provided. By the close contact, reflection on the organ surface can be prevented, and contamination due to the mucous membrane of the organ generated in the window 116 can be ignored. For this reason, in order to determine whether the window 116 is in contact with the external member 10 or to confirm that the external member 10 is not pushed in with too strong force, the exterior member 114b is provided with a contact sensor 118. It has been. The contact sensor 118 detects the contact between the window 116 and the external member 10 and measures the pressing force. When the contact sensor 118 is pressed in a non-contact manner or a pressure exceeding a threshold value, a warning signal is sent to a control means (not shown) of the control system 170. Is a detecting means for transmitting. As will be described later with reference to FIG. 3, the close contact between the information acquisition device 100A and the external member 10 is not necessarily required.

  The optical axis OA1 of the sheet beam generating optical system 130 and the optical axis OA2 of the imaging optical system 150 are arranged in parallel to each other and in parallel to the longitudinal direction of the housing 110A. In FIG. 1, the optical axis OA1 of the sheet beam generating optical system 130 is a broken line before being deflected by the prism 140, and does not include the broken line between the prism 140 and the object 12. Thereby, the diameter of the housing 110A can be reduced. “Parallel” is intended to allow some errors.

  As the laser light source 120, for example, a wavelength variable laser light source is used. In this embodiment, near infrared light (800 nm-2500 nm) is used, but the present invention is not limited to this. The wavelength change by the laser light source 120 is controlled by a control unit (not shown) of the processing / control system 170.

  The excitation light transmission fiber 121 guides the laser light (laser beam) from the laser light source 120 to the sheet beam generation optical system 130. For the excitation light transmission fiber 121, glass, plastic, a hollow member, or the like can be used. Moreover, the light guide member is not limited to this.

  The sheet beam generation optical system 130 generates, from the laser light, a sheet-shaped beam (hereinafter referred to as “sheet beam”) SB that is a convergent light beam in the in-plane direction of FIG. 1 and a parallel light beam in the vertical direction of the paper surface. , A shaping optical system (first optical system) for shaping the excitation light.

  The sheet beam generation optical system 130 includes a plurality of solid lenses 131 to 134, and at least one of the plurality of solid lenses 131 to 134 has a cylindrical surface or an anamorphic surface. As a result, the vertical / horizontal ratio can be changed without using a galvano scanner, and the diameter can be reduced. The configuration of the sheet beam generating optical system 130 is not limited to that shown in FIG. The sheet beam SB can be condensed on the object 12 by the lenses 131, 132, and 134.

  The prism 140 is a deflection member that deflects the light beam by 90 degrees, and other deflection members such as a mirror may be used. In FIG. 1, the light from the sheet beam optical system 130 is deflected. However, as will be described later with reference to FIG. 2, the scattered light from the object may be deflected.

  The window 115 transmits the sheet beam SB and is made of glass or the like. When the object 12 is irradiated with the sheet beam SB that has passed through the window 115, the object 12 emits Raman scattered light RSB, and the Raman scattered light RSB passes through the window 116. Due to the steps provided at the openings of the windows 115 and 116, the sheet beam SB can be prevented from interfering with the window 116 when entering the external member 10 through the window 115. That is, the window 116 is disposed at a position where the sheet beam SB is not incident. Thereby, the possibility that the excitation light enters the image sensor 161 can be reduced.

  The optical axis OA2 of the imaging optical system 150 intersects the sheet beam SB. When the two optical axes OA1 and OA2 are arranged in parallel, it is necessary to arrange a reflecting surface inside or outside the two optical systems 130 and 107 to bend the light beam. Therefore, in this embodiment, the sheet beam generating optical system 130 is used. The prism 140 is arranged on the side close to the object 12.

  The imaging optical system 150 condenses the scattered light generated when the object is irradiated with the sheet-like light. The imaging optical system 150 is an imaging optical system (second optical system) that forms an optical image of the object 12 on the imaging element 161 by Raman scattered light RSL that has passed through the window 116.

  The filter 160 is a narrow-band bandpass filter and has a characteristic of transmitting only a specific wavelength of the light that has passed through the imaging optical system 150. Spectral data can also be acquired by using the filter 160 that changes the wavelength of the laser light source 120 and transmits a specific wavelength in a narrow band. At this time, the wavelength resolution of the spectrum is improved as the bandwidth of the filter 160 is narrowed. Actually, it is desirable that the full width at half maximum is 5 nm or less. The position of the filter 161 is not limited as long as it is disposed between the object 12 and the image sensor 161. For example, the filter 116 may be provided immediately after the window 116 or may be integrated with the window 116.

  The imaging element 161 is a photoelectric conversion element that photoelectrically converts an optical image of the object 12 formed by the imaging optical system 150. The analog electrical signal output from the image sensor 161 is sent to an A / D converter (not shown) of the processing / control system 170 and converted into a digital signal, and signal processing for each week is performed by a signal processing means (not shown). .

  The processing / control system 170 includes an A / D converter (not shown), signal processing means, control means, display means, input means, and storage means, and is configured from a computer. The A / D converter converts an analog signal into a digital signal, and the signal processing means performs various processes on the digital signal. The control means controls the entire information acquisition apparatus. The display means displays an image obtained from the image sensor 161, various control information, warning, status information, and the like. The input means includes a keyboard, a mouse, and the like, and is a means for inputting information. The storage means includes ROM, RAM, and other storage means (memory), and stores images obtained from the image sensor 161, information on the inspection target (external member 10 and target object 12), and the like.

  The light emitted from the laser light source 120 enters the sheet beam generation optical system 130 via the excitation light transmission fiber 121. The light beam incident on the sheet beam generation optical system 130 is converted into a sheet beam SB, deflected 90 degrees by the prism 140, and enters the external member 10 and the object 12 inside the window 115 through the window 115.

  When the object 12 is irradiated with the sheet beam SB, the object 12 emits Raman scattered light RSL, and the Raman scattered light RSL forms an image on the image sensor 161 through the window 116, the imaging optical system 150, and the filter 160. Observed as a Raman scattering image.

  In this embodiment, the optical axis OA1 of the sheet beam generation optical system 130 and the optical axis OA2 of the imaging optical system 150 before being deflected by the prism 140 are arranged in parallel, and are deflected toward the exit side of the sheet beam generation optical system 130. The member is arranged. As a result, the diameter of the housing 110A can be reduced. By providing a step between the opening on the sheet beam generating optical system side and the opening on the imaging optical system side, the sheet beam SB can be incident on the object 12 without interfering with the window 116.

  The sheet beam SB of this embodiment is a parallel light beam in the direction perpendicular to the paper surface, but is not limited to this, and may be a diffused light beam or a convergent light beam in the direction perpendicular to the paper surface. However, the cross-sectional shape of the sheet beam SB at the intersection between the sheet beam SB and the optical axis OA2 of the imaging optical system 150 is orthogonal to the optical axis OA2 of the imaging optical system 150, with the length in the optical axis direction of the imaging optical system 150 being A. When the length in the direction to be taken is B, it is desirable to satisfy the condition of B ≧ 10A. Thereby, it is possible to acquire data having a wide range and high resolution in the depth direction.

  In this embodiment, an image using Raman scattered light is acquired. However, for example, autofluorescence or a dark field image using simple scattered light may be acquired. In that case, the filter 160 is given different characteristics according to the generated fluorescence or scattered light. For example, when detecting fluorescence, the excitation light is cut off and a characteristic that captures fluorescence emitted in a wide band is given.

  Further, the external member 10 shown in FIG. 1 is moved in the optical axis direction (lateral direction) deflected by the prism 140, and the image pickup optical system 150, the filter 160, and the image pickup element 161 are moved in the horizontal direction by the same distance. May be provided. Thereby, a condensing position can be changed in the target object 12, and a three-dimensional image can be acquired.

  The prism 140 may be an optical element including a cylindrical surface or an anamorphic surface. In this case, the prism 140 has a shaping function and becomes a part of the sheet beam generation optical system 130, and the optical axis OA1 of the sheet beam generation optical system 130 before being deflected by the prism 140 is the optical axis of the imaging optical system 150. OA2 becomes parallel.

  FIG. 2 is a partial cross-sectional view of the information acquisition apparatus 100B according to the second embodiment. 2, the same members as those in FIG. 1 are denoted by the same reference numerals. In order to show that the configuration of the sheet beam generating optical system 130 is not limited to that shown in FIG. 1, in FIG. 2, the configuration of the sheet beam generating optical system 130 is changed from that shown in FIG. It has the same function.

  In the second embodiment, a deflection mirror (deflection member) 141 is disposed on the object side of the imaging optical system 150 instead of providing the prism 140. For this reason, in FIG. 1, the Raman scattered light RSL is taken in from the window 116 disposed at the tip (bottom surface) of the housing 110 </ b> A, but in FIG. 2, the Raman scattered light is captured from the window 116 disposed on the side surface of the housing 110 </ b> B. It is taken in.

  As in FIG. 1, the optical axis OA2 of the imaging optical system 150 and the optical axis OA1 of the sheet beam generation optical system 130 are arranged in parallel and in parallel with the longitudinal direction of the housing 110B. “Parallel” in this case is also intended to allow some errors. By the deflection mirror 141 disposed on the object side of the imaging optical system 150, the optical axis OA2 of the imaging optical system 150 is deflected by 90 degrees to become OA3, which intersects the sheet beam SB.

  In this embodiment, the end face 163 of the fiber bundle 162 is disposed in the vicinity of the imaging plane of the image pickup optical system 150 instead of the image pickup element 161. The Raman scattering image formed on the end face 163 is guided to the outside of the information acquisition apparatus 100B through the fiber bundle 162 and imaged.

  The information acquisition apparatus 100B includes a liquid supply unit 165. The liquid supply means 165 supplies a transparent liquid (such as physiological saline) to the third storage unit 113, fills the third storage unit 113 with the liquid, and makes contact even if the window 116 is not in contact with the external member 10. Maintain the same state as you do. Thereby, reflection from the surface of the external member 10 and the surface of the window 116 can be suppressed. Moreover, the object-side numerical aperture (NA) of the imaging optical system 150 can be increased by the liquid, and imaging of weak scattered light is also possible. The liquid transmits both the sheet beam SB and the Raman scattered light RSL.

  In the first and fourth embodiments, the sheet beam SB and the optical axis OA2 of the imaging optical system 150 are orthogonal to each other, but in the second embodiment, the sheet beam SB and the optical axis OA2 of the imaging optical system 150 are parallel. As a result, the image pickup element (or fiber bundle end face) and the surface excited by the sheet beam SB are parallel, and the real image formed on the image pickup element has substantially the same magnification regardless of the angle of view, and image correction is unnecessary. Become. Further, by observing from the orthogonal direction, a direct scattering component from the sheet beam SB is removed, and an image with high contrast can be easily obtained.

  3A and 3B are cross-sectional views of the information acquisition apparatus 100C according to the third embodiment. 3, the same members as those in FIG. 1 are denoted by the same reference numerals. In FIG. 3, the window 116 is not in contact with the external member 10, but may be in contact, or the space may be filled with liquid.

  In the third embodiment, the prism 140 in the first embodiment is replaced with a deflecting mirror 142, and the reflecting surface of the deflecting mirror 142 is moved via a reflecting surface driving unit (rotating unit) 143, so that the object 12 has a sheet beam SB. The position that hits is changed. The reflecting surface driving means 143 is configured by rotating using, for example, a micro motor, or rotating by pulling one of the wires by supporting the deflection mirror 142 and connecting the wires to both ends. can do.

  As shown by the arrow in FIG. 3B, the reflecting surface driving means 143 causes the reflecting surface of the deflecting mirror 142 to rotate around an axis perpendicular to the optical axis OA1, and the position where the sheet beam SB hits the object 12 changes. To do. Thereby, since the surface which emits the Raman scattered light RSL is excited by the sheet beam SB, Raman images of different cross sections can be acquired. A three-dimensional Raman scattering image of the object 12 can be acquired by acquiring and superposing Raman scattering images on each surface.

  Since the position where the Raman scattered light RSL is generated is changed by the movement of the sheet beam SB, when the sheet beam SB rotates, only a part of the Raman scattered light is imaged on the image sensor 161, resulting in a defocused image. End up.

  Therefore, as shown in FIG. 3B, the control means (not shown) calculates the inclination of the image pickup device 161 with respect to the optical axis OA2 based on the Scheinproof principle (the inclination of the object plane × the image magnification), and the image pickup device. The driving unit (first moving unit) 167 is controlled to tilt (rotate) the image sensor 161. Further, the reflection surface driving unit 143 moves the sheet beam SB not only to rotate but also to the optical axis direction of the image sensor 161. For this reason, the control means (not shown) controls the image sensor driving means 167 to not only rotate the image sensor 161 but also move it in the optical axis direction of the image pickup optical system 150.

  By performing the above two operations, even when the reflecting surface of the deflecting mirror 142 is rotated, the image formed on the image sensor 161 becomes an image focused on the entire surface. There is no fixed order of operation, and either may be performed first. Two operations may be performed simultaneously. Of course, when the fiber bundle 162 is used instead of the image sensor 161, the end face 163 is rotated and moved.

  The reflecting surface driving unit 143 may not only rotate the reflecting surface but also move the deflecting mirror 142 along the optical axis OA1. In addition to rotating / moving the image sensor 161, third moving means for performing focus adjustment by rotating / moving at least a part of the imaging optical system 150 may be provided.

  In the present embodiment, the sheet beam SB and the optical axis OA2 of the imaging optical system 150 are not orthogonal. In the arrangement of the first and second embodiments, it is difficult to be directly affected by the excitation light due to the orthogonality. However, if the influence of the direct scattering component is small, it is possible to maintain the imaging relationship by tilting the image sensor 161 and the imaging optical system 150 based on the Scheinproof principle, as in this embodiment. At this time, the magnification of the captured image varies depending on the position of the screen. However, the control unit (not shown) calculates the magnification at each position in the screen from the inclination of the image sensor 161 and the sheet beam SB at the time of imaging. It is sufficient to correct the magnification.

  4A and 4B are cross-sectional views of the information acquisition apparatus 100D according to the fourth embodiment. 4, the same members as those in FIG. 1 are denoted by the same reference numerals. In the fourth embodiment, the prism 140 is translated along the optical axis OA1 of the sheet beam generating optical system 130 to change the position of the sheet beam SB.

  As shown in FIG. 4A, the information acquisition apparatus 100D includes a prism moving unit 145 that moves the prism 140 along the optical axis OA1, and a lens moving unit 158 that moves the imaging optical system 150 along the optical axis OA2. Is different from the information acquisition apparatus 100A in that

  The prism moving means (second moving means) 145 is, for example, a moving mechanism using a linear motor, a moving mechanism using a cam, or by connecting a wire to the upper and lower ends of a member holding the prism and pulling one of the wires. A moving mechanism is conceivable.

  The prism 140 is moved in the optical axis direction of the sheet beam generating optical system 130 by the prism moving unit 145. The prism 140 is a 90-degree right-angle prism. As the prism 140 moves, the sheet beam SB moves in the optical axis direction of the imaging optical system 150. As a result, the position where the sheet beam SB hits the external member 10 and the object 12 changes, and images from different positions can be captured.

  When the sheet beam SB moves in the optical axis direction of the image pickup optical system 150, the image on the image pickup device 161 is not in focus. For this reason, as shown in FIG. 4B, a part of the lens (focus lens) 156 of the imaging optical system 150 is moved by the lens moving unit 158 (third moving unit) to perform focus adjustment. As a result, it is possible to always form an in-focus image on the image sensor 161 in accordance with the movement of the sheet beam SB. In addition, it is possible to obtain a three-dimensional image of the object 12 by superimposing images at each position of the sheet beam SB.

  Driving of the prism moving unit 145 and the lens moving unit 158 is controlled by a control unit (not shown). Further, the movement of the prism 140 and the movement of the imaging optical system 150 may be performed simultaneously. FIG. 5 is a plan view showing this example.

  In FIG. 5, the movement of the prism 140 and the movement of the lens 156 are performed simultaneously by the two cam structures 182 and 183 engaged with one rotating shaft (shaft) 181 coupled to the motor shaft of the motor 180. ing. In this embodiment, a part of the imaging optical system 150 is moved for focusing. However, the sixth moving unit may adjust the focus by moving all of the imaging optical system 150 or the imaging element 161. Good. That is, it is sufficient for the sixth moving unit to adjust the focus by changing the relative position of the imaging element 161 and the focal position formed by the imaging optical system 150.

  The present invention can be applied to the use of acquiring in-vivo information by fluorescence or Raman scattered light.

  116 ... Window, 130 ... Sheet beam generation optical system (first optical system), 150 ... Imaging optical system (second optical system), 160 ... Filter

Claims (23)

A first optical system having an optical element including a cylindrical surface or an anamorphic surface, and shaping light from a light source into sheet-like light;
A second optical system that collects scattered light generated when the object is irradiated with the sheet-like light;
Have
An information acquisition apparatus, wherein an optical axis of the first optical system and an optical axis of the second optical system are parallel to each other.   The information acquisition apparatus according to claim 1, further comprising a deflecting member that deflects light from the first optical system or scattered light from the object.   The information acquisition apparatus according to claim 1, further comprising a filter that transmits only light having a specific wavelength in the scattered light from the object.   4. The information acquisition apparatus according to claim 1, further comprising a window that is disposed at a position where the light from the first optical system does not enter and through which the scattered light passes. 5. A housing that includes the window and houses the first optical system and the second optical system;
The information acquisition apparatus according to claim 4, wherein the casing has a step between an opening through which the light shaped by the first optical system passes and the window.   6. The information acquisition apparatus according to claim 4, further comprising detection means for detecting contact between the window and an external member.   The information acquisition apparatus according to claim 6, wherein the detection unit further detects whether or not a pressure between the window and the external member is a threshold value or more.   The information acquiring apparatus according to claim 2, wherein the deflecting member deflects light from the first optical system and guides the light to the object.   The information acquiring apparatus according to claim 8, wherein the deflecting member deflects the light beam from the first optical system by 90 degrees.   The information acquiring apparatus according to claim 2, wherein the deflection member deflects scattered light from the object and guides the light to the second optical system.   The information acquisition apparatus according to claim 10, wherein the deflecting member deflects a light beam from the second optical system by 90 degrees.   The information acquisition apparatus according to claim 4, further comprising a liquid supply unit that supplies a liquid that transmits the scattered light between the window and the object.   The information acquisition apparatus according to claim 1, further comprising an image sensor that photoelectrically converts an optical image formed by the second optical system.   The information acquisition apparatus according to claim 1, further comprising a fiber bundle that guides an optical image formed by the second optical system. Rotating means for rotating the deflecting member around an axis perpendicular to the optical axis of the first optical system;
An image sensor that photoelectrically converts an optical image formed by the second optical system;
First moving means for rotating the image sensor with respect to the optical axis of the second optical system and moving the imaging element in the optical axis direction of the second optical system;
The information acquisition apparatus according to claim 2, further comprising:   The information acquisition apparatus according to claim 15, further comprising means for performing magnification correction according to a position in a screen of an image obtained from the image sensor. Rotating means for rotating the deflecting member around an axis perpendicular to the optical axis of the first optical system;
A fiber bundle for guiding an optical image formed by the second optical system;
First moving means for rotating the end face of the fiber bundle with respect to the optical axis of the second optical system and moving the end surface of the fiber bundle in the optical axis direction of the second optical system;
The information acquisition apparatus according to claim 2, further comprising:   18. The information acquisition apparatus according to claim 15, further comprising a second moving unit configured to move the deflecting member in an optical axis direction of the first optical system.   The information acquisition apparatus according to any one of claims 15 to 18, further comprising a third moving unit that adjusts a focus by moving at least a part of the second optical system. An image sensor that photoelectrically converts an optical image formed by the second optical system;
Second moving means for moving the deflection member in the optical axis direction of the first optical system;
A third moving means for performing focus adjustment by changing a focal position formed by the second optical system and a relative position of the image sensor;
The information acquisition apparatus according to claim 2, further comprising: An image sensor that photoelectrically converts an optical image formed by the second optical system;
Focus adjustment is performed by moving the deflecting member in the optical axis direction of the first optical system, and changing a focal position formed by the second optical system and a relative position of the imaging element. Means to do simultaneously,
The information acquisition apparatus according to claim 2, further comprising:   The information acquisition apparatus according to claim 20 or 21, wherein an angle at which the light shaped by the first optical system intersects with an optical axis of the second optical system is 90 degrees.   The information acquisition apparatus according to any one of claims 1 to 22, wherein the information acquisition apparatus is an endoscope.