JP2011050667A - Optical scan type endoscope - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce transmission loss between an optical scan type endoscope and a light source unit without enhancing positioning precision. <P>SOLUTION: The optical scan type endoscope 30 includes a scanning fiber 33. The scanning fiber 33 is formed of a connection fiber part 33c, an emission fiber part 33o and an optical adapter 33a. The connection fiber 33c which is a GI type multimode fiber and the emission fiber part 33o which is a single mode fiber are optically coupled by the optical adapter 33a. An end part on the side of the connection fiber part 33c is arranged at a connector 32, and an end part on the side of the emission fiber part 33o is arranged at the distal end of an insertion tube 31. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a reduction in transmission loss between an optical scanning endoscope and a light source unit without increasing alignment accuracy.

  An optical scanning endoscope has been proposed (see Patent Document 1). In order to capture an image with an optical scanning endoscope, it is necessary to irradiate light to a minute region in the observation target region. In order to irradiate a minute region with illumination light or the like, a single mode fiber that suppresses divergence of emitted light is used.

  The light source unit and the optical scanning endoscope are detachable so that illumination light can be supplied to various types of optical scanning endoscopes. When connecting the optical scanning endoscope to the light source unit, it is necessary to optically connect the single mode fiber in the optical scanning endoscope to the single mode fiber provided in the light source unit. That is, it is necessary to match the cores of both single mode fibers.

  However, the core diameter of the single mode fiber is extremely small (5 to 10 μm), and it is difficult to match the cores at the time of connection in a detachable configuration. Therefore, it has been difficult to supply a sufficient amount of illumination light or the like to the optical scanning endoscope.

International Publication No. 2007/084915 Pamphlet

  Accordingly, an object of the present invention is to provide an optical scanning endoscope capable of receiving a sufficient amount of illumination light or the like from a light source unit.

  The optical scanning endoscope according to the present invention is disposed at the distal end of the insertion tube from the first end portion detachably connected to the light source system that supplies the irradiation light irradiated to the subject. A scanning fiber having a connection fiber portion that transmits irradiation light to the end portion of the GI-type multimode fiber and has at least a first end portion, and a second end while the irradiation light is incident on the first end portion. And an actuator that scans irradiation light by displacing the portion.

  Note that the entire scanning fiber is preferably formed of a GI type multimode fiber.

  The scanning fiber preferably has an outgoing fiber portion that is optically connected to the connecting fiber portion and extends to the second end portion side and is formed by a single mode fiber.

  Further, it is preferable that the connecting fiber portion and the outgoing fiber portion are optically coupled by different diameter fusion splicing or an optical adapter.

  Moreover, it is preferable that the connection fiber part is a TEC fiber in which the core system is expanded on the first end side.

  Moreover, it is preferable that the scanning fiber has a multimode optical coupler that is provided in the connection fiber portion and branches light transmitted from the second end portion toward the second end portion.

  According to the present invention, the end portion detachably connected to the light source system has a connection fiber portion that is a GI type multimode fiber, and the core diameter is larger than the mode field diameter of the single mode fiber. It is possible to reduce transmission loss even if the alignment accuracy at the time of connection is low.

1 is an external view schematically showing an external appearance of an optical scanning endoscope apparatus to which a first embodiment of the present invention is applied. FIG. It is a block diagram which shows roughly the internal structure of an optical scanning type endoscope processor. 1 is a structural diagram schematically showing an internal configuration of an optical scanning endoscope according to a first embodiment. It is a figure explaining the influence of the shift | offset | difference of the optical axis of a connection fiber and a connection fiber part when connecting the conventional optical scanning endoscope to an endoscope processor. It is a figure explaining the influence of the shift | offset | difference of the optical axis of a connection fiber and a connection fiber part when connecting the optical scanning endoscope of this embodiment to an endoscope processor. FIG. 6 is a structural diagram schematically illustrating an internal configuration of an optical scanning endoscope according to a second embodiment. It is a figure explaining the state which welded the connecting fiber part and the outgoing fiber part into different diameters.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is an external view schematically showing an external appearance of an optical scanning endoscope apparatus having an optical scanning endoscope to which the first embodiment of the present invention is applied.

  The optical scanning endoscope apparatus 10 includes an optical scanning endoscope processor 20, an optical scanning endoscope 30, and a monitor 11. The optical scanning endoscope processor 20 is connected to the optical scanning endoscope 30 and the monitor 11.

  Light to be applied to the observation target area OA is supplied from the optical scanning endoscope processor 20. The supplied light is transmitted to the distal end of the insertion tube 31 by a scanning fiber (not shown in FIG. 1), and is irradiated toward one point (see reference numeral P1) in the observation target region.

  The direction of the distal end of the scanning fiber is changed by an actuator (not shown in FIG. 1). By changing the direction of the end portion, the light irradiated from the scanning fiber is scanned over the observation target region. The actuator is controlled by the optical scanning endoscope processor 20.

  The reflected light scattered at the light irradiation position is transmitted to the optical scanning endoscope processor 20 by a light receiving fiber (not shown in FIG. 1). The optical scanning endoscope processor 20 generates a pixel signal corresponding to the amount of reflected light received. An image signal for one frame is generated by generating a pixel signal for the entire region to be scanned. The generated image signal is transmitted to the monitor 11 and an image corresponding to the image signal is displayed on the monitor 11.

  Next, the configuration of the optical scanning endoscope processor 20 will be described. As shown in FIG. 2, the optical scanning endoscope processor 20 includes a light source unit 21, a light receiving unit 22, a scan driving circuit 23, an image signal processing circuit 24, a timing controller 25, and the like.

  When the connector 32 (see FIG. 1) of the optical scanning endoscope 30 is fitted to the endoscope terminal (not shown) of the optical scanning endoscope processor 20, the connection provided in the scanning fiber 33 and the light source unit 21 is performed. The optical fiber 21c and the light receiving fiber 34 and the light receiving unit 22 are optically connected. As will be described later, the incident end of the scanning fiber 33, which is a GI type multimode fiber, and the connection fiber 21c, which is a single mode fiber, are optically connected.

  Further, when the connector 32 is fitted to the endoscope terminal, the scan drive circuit 23 and the actuator 35 provided in the optical scanning endoscope 30 are electrically connected.

  The light source unit 21 is provided with a laser light source (not shown) that emits a red light laser, a green light laser, and a blue light laser. The red light laser, green light laser, and blue light laser emitted from the respective laser light sources are mixed by an optical coupler (not shown) formed by a mirror (not shown) and an optical filter (not shown). It can be emitted as a white light laser.

  The light source unit 21 is provided with a connection fiber 21c formed of a single mode fiber. The connecting fiber 21c is arranged so that the white light laser mixed by the optical coupler is incident on the connecting fiber 21c.

  As described above, the scanning fiber 33 is connected to the connection fiber 21 c of the light source unit 21, and white light is supplied to the scanning fiber 33. The scan drive circuit 23 causes the actuator 35 to drive the scanning fiber 33 to displace the irradiation position of the light emitted from the scanning fiber 33.

  As described above, the reflected light of the observation target region irradiated with the light is transmitted to the optical scanning endoscope processor 20 through the light receiving fiber 34. The light transmitted to the optical scanning endoscope processor 20 enters the light receiving unit 22.

  The light receiving unit 22 has a spectroscope (not shown) formed by a mirror (not shown) and an optical filter (not shown), and light incident on the light receiving unit 22 is red light, green light, and Spectroscopy into blue light. The light receiving unit 22 is provided with photomultiplier tubes (not shown) corresponding to red light, green light, and blue light. Each photomultiplier tube generates a pixel signal corresponding to the amount of received light of red light, green light, and blue light.

  The pixel signal is transmitted to the image signal processing circuit 24. In the image signal processing circuit 24, the pixel signal is stored in the image memory 26. When the pixel signal corresponding to the entire observation target region is stored, the image signal processing circuit 24 performs predetermined signal processing on the pixel signal and transmits it to the monitor 11 via the encoder 27 as an image signal of one frame.

  The light source unit 21, the light receiving unit 22, the scan drive circuit 23, the image signal processing circuit 24, and the encoder 27 are controlled by the timing controller 25 at the timing of operation of each part.

  Next, the configuration of the optical scanning endoscope 30 will be described. As shown in FIG. 3, the optical scanning endoscope 30 is provided with a scanning fiber 33, a light receiving fiber 34, an actuator 35, a photographing lens 36, and the like.

  Inside the connector 32, the end of the scanning fiber 33, the end of the light receiving fiber 34, and the terminal of the signal line connecting the actuator 35 and the scan drive circuit 23 are fixed at predetermined positions.

  Further, inside the endoscope terminal, the end of the connection fiber 21c, the light receiving unit 22, and the terminal of the signal line connecting the actuator 35 and the scan drive circuit 23 are also fixed at predetermined positions.

  When the connector 32 is fitted to the endoscope terminal, the scanning fiber 33 and the connection fiber 21c are optically connected, the light receiving fiber 34 and the light receiving unit 22 are optically connected, and the signal line terminals are electrically connected to each other. The positions within the connector 32 and the endoscope terminal are determined so as to be connected to each other.

  The scanning fiber 33 extends from the connector 32 to the distal end of the insertion tube 31. The scanning fiber 33 includes a connection fiber portion 33c, an output fiber portion 33o, and an optical adapter 33a.

  The connecting fiber portion 33c is formed of a GI type multimode fiber. The outgoing fiber portion 33o is formed of a single mode fiber. The connecting fiber portion 33c and the outgoing fiber portion 33o are optically coupled by the optical adapter 33a. The scanning fiber 33 is provided in the optical scanning endoscope 30 so that the connection fiber 33 c is disposed at the connector 32 and the output fiber 33 o is disposed at the distal end of the insertion tube 31.

  As described above, the white light laser emitted from the light source unit 21 is incident on the incident end (first end) of the scanning fiber 33 through the connection fiber 21c. The white light incident on the incident end is transmitted to the emission end (second end) side. The transmitted white light is emitted from the emission end, passes through the photographing lens 36, and is irradiated on the observation target region.

  An actuator 35 is provided near the exit end of the scanning fiber 33. The actuator 35 can bend the exit end of the scanning fiber 33 in two directions perpendicular to the longitudinal direction.

  The exit end of the scanning fiber 33 is driven to vibrate while repeatedly increasing and decreasing in amplitude along two directions perpendicular to the longitudinal direction of the scanning fiber 33, and is displaced so as to pass through a spiral displacement path. The white light is scanned over the observation target region by being displaced so as to pass through the spiral displacement path.

  The reflected light at one point of the observation target area OA irradiated with the light is scattered, and the scattered reflected light enters the incident end of the reflected optical fiber 34. A plurality of reflection optical fibers 34 are provided in the optical scanning endoscope 30. Scattered light at one point on the observation target area OA enters each reflected optical fiber 34 and is transmitted to the light receiving unit 22.

  According to the optical scanning endoscope 30 configured as described above, the scanning fiber 33 provided in the optical scanning endoscope 30 and the light source unit 21 provided in the optical scanning endoscope processor 20 are detachable. It is possible to reduce the transmission loss of light from the light source unit 21 to the scanning fiber 33 while having a connectable configuration. The reduction of transmission loss will be described below.

  The more the core or mode field of the optical fiber that emits light is displaced from within the core or mode field of the optical fiber that receives light, the greater the transmission loss in the connection of the optical fiber. In the conventional configuration, since the entire scanning fiber is formed of a single mode fiber having a small mode field diameter, transmission loss increases even if the optical axes of the scanning fiber and the connecting fiber are slightly shifted.

  For example, as shown in FIG. 4, in the connection of single mode fibers having mode field diameters of 5.0 μm, when the centers of the optical axes are shifted by 2.5 μm, more than half of the area of the mode field of the connecting fiber is Does not overlap the mode field of the scanning fiber.

  On the other hand, in the optical scanning endoscope 30 of the present embodiment, the incident end of the scanning fiber 33 is a multimode fiber having a core diameter larger than that of the single mode fiber. Therefore, even if the optical axes of the scanning fiber 33 and the connecting fiber 21c are slightly shifted, there is a high possibility that the mode field of the connecting fiber 21c overlaps the core of the scanning fiber 33.

  For example, as shown in FIG. 5, in the connection between the scanning fiber 33 whose core diameter at the input end is 50.0 μm and the connection fiber 21 c whose mode field diameter is 5.0 μm, the center of each optical axis is 10 Even in the case of a deviation of 0.0 μm, the mode field of the connecting fiber 21 c overlaps the core of the scanning fiber 53.

  As described above, by making the incident end of the scanning fiber 33 a multi-mode fiber, the tolerance of the optical axis shift in the connection with the connection fiber 21c is increased, so that the scanning fiber 33 and the connection fiber 21c are made high. It is possible to reduce transmission loss even if alignment is not performed with accuracy.

  In addition, since a single mode is maintained by using a GI type multimode fiber, it is possible to irradiate a minute region in the observation target region with white light.

  Next, an optical scanning endoscope to which the second embodiment of the present invention is applied will be described. The optical scanning endoscope according to the second embodiment is different from the first embodiment in that it includes an optical coupler. Hereinafter, a description will be given focusing on differences from the first embodiment. In addition, the same code | symbol is attached | subjected to the site | part which has the same function as 1st Embodiment.

  As shown in FIG. 6, the optical scanning endoscope 300 is provided with a scanning fiber 33, a light receiving fiber 34, an actuator 35, a photographing lens 36, and the like, as in the first embodiment. Furthermore, unlike the first embodiment, the optical scanning endoscope 300 is provided with a multimode optical coupler 37.

  The multimode optical coupler 37 is provided in the connection fiber portion 33c. A connection fiber 12 c extending from the external light source device 12 is detachable from the multimode optical coupler 37. The multi-mode optical coupler 37 is an optical coupler that branches light transmitted from the exit end side to the entrance end side of the scanning fiber 33. Accordingly, light incident from the incident end of the connection fiber portion 33c and / or light incident from the connection fiber 12c is transmitted to the output end. Further, the light incident on the exit end is branched and transmitted to the entrance end of the connection fiber portion 33c and the connection fiber 12c.

  Therefore, when the connection fiber 12 c is connected to the multimode optical coupler 37, the light emitted from the external light source device 12 is also transmitted to the emission end of the scanning fiber 33. The external light source device 12 emits, for example, an excimer die laser used for PDT.

  In the optical scanning endoscope according to the second embodiment configured as described above, transmission loss can be reduced as in the first embodiment. Furthermore, in the second embodiment, a laser beam corresponding to a specific purpose such as PDT can be emitted from the emission end of the scanning fiber 33.

  In the first and second embodiments, the connection fiber portion 33c and the output fiber portion 33o are optically coupled by the optical adapter 33a, but may be optically coupled by other methods. . For example, as shown in FIG. 7, a configuration may be employed in which a connection fiber portion 33c that is a multimode fiber and an output fiber portion 33o that is a single mode fiber are coupled by different diameter fusion connection.

  In the first and second embodiments, the connection fiber portion 33c uses a multimode fiber having a constant core system. However, a TEC fiber that expands the core system on the incident end side may be used. .

  In the first and second embodiments, the scanning fiber 33 is configured by the connection fiber portion 33c that is a multimode fiber and the output fiber portion 33o that is a single mode fiber. May be formed of a GI type multimode fiber. Even if the entire scanning fiber 33 is a GI type multimode fiber, it is possible to increase the tolerance of the optical axis shift in connection with the connection fiber 21c.

  In the first and second embodiments, the light source unit 21 emits white light. However, at least one type of light of red light, green light, and blue light may be separately emitted. In addition, the configuration may be such that light in a different band is emitted. For example, excitation light that causes the biological tissue to emit fluorescence may be emitted.

  Further, in the second embodiment, the external light source device 12 is optically connected to the multimode optical coupler 37 and the light for irradiating the subject is supplied to the scanning fiber 33. It is also possible to connect an external light receiving device. Reflected light or emitted fluorescence with respect to the irradiation light of the subject also enters the scanning fiber 33. Therefore, it is also possible to detect reflected light or the like incident on the scanning fiber 33 by an external light receiving device.

DESCRIPTION OF SYMBOLS 10 Optical scanning endoscope apparatus 11 Monitor 20 Optical scanning endoscope processor 21 Light source unit 21c Connection fiber 22 Light receiving unit 23 Scan drive circuit 24 Image signal processing circuit 25 Timing controller 26 Image memory 27 Encoder 30, 300 Optical scanning Type Endoscope 31 Insertion Tube 32 Connector 33 Scanning Fiber 33a Optical Adapter 33c Connection Fiber Part 33o Outgoing Fiber Part 34 Receiving Fiber 35 Actuator 36 Shooting Lens 37 Multimode Optical Coupler

Claims (6)

Transmitting the irradiation light from a first end detachably connected to a light source system for supplying irradiation light irradiated to a subject to a second end disposed at a distal end of the insertion tube; A scanning fiber having at least the first end portion of a connecting fiber portion formed by a GI-type multimode fiber;
An optical scanning endoscope, comprising: an actuator that scans the irradiation light by displacing the second end while the irradiation light is incident on the first end.   The optical scanning endoscope according to claim 1, wherein the entire scanning fiber is formed by the GI type multimode fiber.   2. The light according to claim 1, wherein the scanning fiber is optically connected to the connection fiber portion, extends toward the second end portion, and has an output fiber portion formed by a single mode fiber. Scanning endoscope.   The optical scanning endoscope according to claim 3, wherein the connection fiber portion and the output fiber portion are optically coupled by different diameter fusion splicing or an optical adapter.   5. The optical scanning type internal vision according to claim 1, wherein the connection fiber portion is a TEC-type fiber having a core system expanded on the first end portion side. mirror.   The scanning fiber includes a multimode optical coupler provided in the connection fiber portion and for branching light transmitted from the second end portion toward the first end portion. The optical scanning endoscope according to claim 5.

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