JP2011041754A - Optical scanning endoscope - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make it possible to make thin the diameter of an inserting pipe of an optical scanning endoscope. <P>SOLUTION: The optical scanning endoscope 50 includes a scanning fiber 53, an actuator 54, light receiving fibers 55, and an optical coupler 56. The scanning fiber 53 is formed of a GI type multimode fiber. The actuator 54 supports the scanning fiber 53 in the vicinity of the distal end thereof. The actuator 54 bends the scanning fiber 53 in two directions perpendicular to the longitudinal direction of the scanning fiber 53. The scanning fiber 53 is formed of the GI type multimode fiber. The reflected light of a subject is incident on the distal end of the scanning fiber 53. The scanning fiber 53 transmits the reflected light to a proximal end side. The optical coupler 56 branches the scanning fiber 53 into the light receiving fibers 55 near the distal end. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to reducing the diameter of an insertion tube of an optical scanning endoscope.

  An optical scanning endoscope has been proposed (see Patent Document 1). In the optical scanning endoscope, since there is no need to provide an image sensor at the tip of the insertion tube, the diameter of the insertion tube can be reduced while improving the resolution. However, further reduction in diameter of the insertion tube has been demanded.

International Publication No. 2007/084915 Pamphlet

  Therefore, an object of the present invention is to reduce the diameter of the insertion tube of the optical scanning endoscope.

  An optical scanning endoscope according to the present invention includes an insertion tube that is inserted into a body or a structure from an insertion end, a first end portion that is inserted into the insertion tube and is disposed on the insertion end side, and a first end portion. Transmits the irradiation light incident on the second end on the opposite side to the first end and transmits at least one of reflected light from the subject illuminated by the irradiation light and autofluorescence from the first end to the second end. Light guide means that transmits to the end portion and has a multimode fiber, and the light guide means has a refractive index that decreases as it moves away from the optical axis at least in the vicinity of the first end portion, and is incident on the second end portion. Is characterized in that the subject is scanned by the displacement of the first end.

  The light guiding means is preferably a GI type multimode fiber. Alternatively, the first optical system is preferably a GRIN lens.

  The light guiding means preferably has a GRIN lens disposed at the first end of the multimode fiber.

  In addition, it is preferable to include an optical coupler that is provided in the vicinity of the second end portion and branches at least one of reflected light and autofluorescence transmitted from the first end portion to the second end portion.

  An optical scanning endoscope apparatus according to the present invention includes an insertion tube that is inserted into a body or a structure from an insertion end, a first end that is inserted into the insertion tube, and is disposed on the insertion end side. Transmits the irradiation light incident on the second end on the opposite side to the first end and transmits at least one of reflected light from the subject illuminated by the irradiation light and autofluorescence from the first end to the second end. A light guide means having a multimode fiber transmitted to the end, the light guide means having a refractive index that decreases with increasing distance from the optical axis at least in the vicinity of the first end, and is incident on the second end. The light is an optical scanning endoscope that scans the subject when the first end portion is displaced, a light source that supplies irradiation light to the second end portion, reflected light that is branched by an optical coupler, and / or home. And a light receiving portion that receives fluorescence and generates a pixel signal.

  According to the present invention, since the reflected light can be incident on the optical fiber used for transmitting the illumination light with a sufficient amount of light, an optical fiber for transmitting the reflected light becomes unnecessary. Therefore, the diameter of the insertion tube can be reduced.

1 is an external view schematically showing the external appearance of an optical scanning endoscope apparatus to which an embodiment of the present invention is applied. It is a block diagram which shows roughly the internal structure of an optical scanning type endoscope processor. It is a block diagram which shows typically the internal structure of an optical scanning endoscope. It is a front view of the front-end | tip of the insertion tube of the conventional optical scanning endoscope. It is a front view of the front-end | tip of the insertion tube of the optical scanning endoscope of this embodiment.

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 50, and a monitor 11. The optical scanning endoscope processor 20 is connected to the optical scanning endoscope 50 and the monitor 11.

  In the following description, the distal end of the scanning fiber (not shown in FIG. 1) is an end portion disposed on the distal end side (insertion end) of the insertion tube 51 of the optical scanning endoscope 50, and The end is an end portion disposed on the connector 52 connected to the optical scanning endoscope processor 20.

  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 51 by the scanning fiber, and is irradiated toward one point (see reference numeral P1) in the observation target region. Reflected light at one point on the observation target region irradiated with light is transmitted from the distal end of the insertion tube 51 to the optical scanning endoscope processor 20 by the scanning fiber.

  The direction of the tip of the scanning fiber is changed by an actuator (not shown in FIG. 1). By changing the direction of the tip, 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 optical scanning endoscope processor 20 receives light scattered at the light irradiation position and generates a pixel signal corresponding to the amount of 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.

  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.

  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.

  White light emitted from the light source unit 21 is supplied to the scanning fiber 53. The scan drive circuit 23 causes the actuator 54 to drive the scanning fiber 53. As will be described later, the reflected light from the observation target region irradiated with the light is transmitted to the optical scanning endoscope processor 20 through the scanning fiber 53 and the light receiving fiber 55. 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.

  When the optical scanning endoscope processor 20 and the optical scanning endoscope 50 are connected, the light source unit 21 and the scanning fiber 53 provided in the optical scanning endoscope 50, and the light receiving unit 22 and the light receiving fiber 55 are connected. Are optically connected to each other. When the optical scanning endoscope processor 20 and the optical scanning endoscope 50 are connected, the scan driving circuit 23 and the actuator 54 provided in the optical scanning endoscope 50 are electrically connected.

  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 50 will be described. As shown in FIG. 3, the optical scanning endoscope 50 is provided with a scanning fiber 53, an actuator 54, a light receiving fiber 55, an optical coupler 56, and the like.

  The scanning fiber 53 extends from the connector 52 to the distal end of the insertion tube 51. As described above, the beam-shaped white light emitted from the light source unit 30 enters the proximal end of the scanning fiber 53. White light incident on the proximal end is transmitted to the distal end side. The transmitted white light is emitted from the tip, passes through the photographing lens 57, and is irradiated onto the observation target region.

  The scanning fiber 53 is formed of a GI type multimode fiber. By the GI type multimode fiber, the white light laser incident on the proximal end is transmitted to the distal end without substantially causing mode dispersion. Therefore, it is possible to irradiate white light from the tip of the scanning fiber 53 to one minute point in the observation target region.

  An actuator 54 is provided near the exit end of the scanning fiber 53. The actuator 54 can bend the tip of the scanning fiber 53 in two directions perpendicular to the longitudinal direction.

  The distal end of the scanning fiber 53 is driven to vibrate while repeatedly increasing and decreasing in amplitude along two directions perpendicular to the longitudinal direction of the scanning fiber 53, 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.

  White light emitted from the tip of the scanning fiber 53 passes through the photographing lens and is emitted toward one point in the observation target region. Reflected light at one point of the observation target region irradiated with light is scattered, and the scattered light enters the tip of the scanning fiber 53.

  The reflected light incident on the scanning fiber 53 is transmitted to the proximal end side of the scanning fiber 53. Inside the connector 52, the scanning fiber 53 is branched into two fibers by a multimode optical coupler 56. One fiber is connected to the light source unit 21 as a scanning fiber 53, and the other fiber is connected to the light receiving unit 22 as a light receiving fiber 55.

  As described above, the light receiving unit 22 detects the received light amount of each of the red light component, the green light component, and the blue light component of the reflected light, and generates a pixel signal corresponding to each received light amount. The pixel signal is transmitted to the image signal processing circuit 24.

  In the image signal processing circuit 24, the light irradiation position at the moment is estimated based on a signal for controlling the scan driving circuit 23. The image signal processing circuit 24 stores the received image signal at the address of the image memory 26 corresponding to the estimated position.

  As described above, the irradiation light is scanned on the observation target region, and a pixel signal is generated based on the reflected light at each position and stored in the address of the corresponding image memory 26. An image signal corresponding to the image of the observation target region is formed by the pixel signal at each position stored between the scanning start point and the scanning end point. The image signal is subjected to predetermined signal processing as described above and then transmitted to the monitor 11.

  As described above, according to the optical scanning endoscope of the present embodiment, using only the scanning fiber 53, transmission of light irradiated from the light source unit 21 to the distal end of the insertion tube 51 and reflection of the subject are performed. Since light can be transmitted to the light receiving unit 22, the diameter of the insertion tube 51 can be reduced.

  In a conventional optical scanning endoscope, a single mode fiber is used as a scanning fiber in order to irradiate light toward a minute point in an observation target region. However, since the core diameter of the single mode fiber is extremely smaller than that of the multimode fiber, it is difficult to make the reflected light from the observation target region incident with a sufficient amount of light. Therefore, in order to transmit the reflected light to the light receiving unit 22, it is necessary to provide a light receiving optical fiber 58 different from the scanning fiber 53 (see FIG. 4), and it is difficult to further reduce the diameter of the insertion tube 51 ′. It was.

  However, in the present embodiment, by using a GI type multimode fiber for the scanning fiber 53, it is possible to irradiate light toward one minute point in the observation target region, while sufficiently reflecting the reflected light at the point irradiated with light. It is possible to enter with a small amount of light. Therefore, it is not necessary to provide an optical fiber for transmitting the reflected light to the light receiving unit 22 separately from the scanning fiber 53, so that the diameter of the insertion tube 51 can be reduced (see FIG. 5).

  In this embodiment, the GI type multimode fiber is used for the scanning fiber 53. However, it is possible to irradiate light from a tip of the scanning fiber 53 to a minute point and to sufficiently reflect the reflected light from the subject. Any optical fiber may be used. For example, an optical system in which the refractive index continuously decreases as the distance from the optical axis is used as an alternative to the scanning fiber 53, or the optical system may be fixed to the tip of the scanning fiber 53. Specifically, even if a GRIN lens is provided in the step index type multimode fiber, the same effect as in this embodiment can be obtained.

  In the present embodiment, the scanning fiber 53 is branched into two fibers by the multimode optical coupler 56, and the reflected light incident on the tip can be transmitted to the light receiving unit 22, but other mechanisms are used. The configuration may be such that the reflected light is obtained from the scanning fiber 53 and transmitted to the light receiving unit 22.

  Moreover, in this embodiment, although it is the structure which radiate | emits white light from the light source unit 21, the structure which radiate | emits the excitation light which makes a biological tissue light-emit autofluorescence may be sufficient. In such a configuration, the autofluorescence at the position irradiated with the excitation light is transmitted to the light receiving unit 22 via the scanning fiber 53 and the light receiving fiber 55.

DESCRIPTION OF SYMBOLS 10 Optical scanning type endoscope apparatus 50 Optical scanning type endoscope 51 Insertion tube 53 Scanning fiber 54 Actuator 55 Light receiving fiber 56 Optical coupler

Claims (5)

An insertion tube inserted into the body or structure from the insertion end;
Inserted into the insertion tube, a first end is disposed on the insertion end side, and irradiation light incident on a second end opposite to the first end is incident on the first end A light guide means for transmitting at least one of reflected light and autofluorescence from the subject illuminated by the irradiation light from the first end portion to the second end portion and having a multimode fiber. ,
The light guiding means has a refractive index that decreases with increasing distance from the optical axis at least in the vicinity of the first end.
The irradiation light incident on the second end portion scans the subject when the first end portion is displaced. An optical scanning endoscope.   The optical scanning endoscope according to claim 1, wherein the light guiding unit is a GI type multimode fiber.   The optical scanning endoscope according to claim 1, wherein the light guide unit includes a GRIN lens disposed at the first end of the multimode fiber.   An optical coupler is provided in the vicinity of the second end, and branches at least one of the reflected light and the autofluorescence transmitted from the first end to the second end. The optical scanning endoscope according to any one of claims 1 to 3. An optical scanning endoscope according to claim 4,
A light source for supplying the irradiation light to the second end;
An optical scanning endoscope apparatus comprising: a light receiving unit that receives the reflected light and / or the autofluorescence branched by the optical coupler and generates a pixel signal.

Images